Medical News

Digestive Health Research

While progress is being made in our understanding of the gastrointestinal disorders, important questions remain. For example:

• What causes the disorders?
• Why do certain people get them?
• How do we best treat the conditions?
• How do we prevent the disorders?
• How do we cure them?

Sound medical research is needed to explore these questions. Here we report a sampling of research studies that provide clues to better understanding GI disorders. Each new study adds a small piece to the puzzle, making the big picture clearer.

Get the latest IBS news, updates & info. from IFFGD sent to you by email. Subscribe to IBS UPDATES here.

To learn more about medical research, visit our web site at www.giResearch.org.

News you can use: a sampling of published studies

Obesity and GERD

In a study that looked at data from 1,659 patients with reflux symptoms, researchers at the University of Southern California (USC) found a link between obesity and GERD. GERD is a condition which develops when the back-flow (reflux) of stomach contents causes troublesome symptoms and/or complications.

Compared to patients with normal weight, obese patients were more than twice as likely to have a defective LES, the muscle that acts as a valve to prevent acid reflux. The study concluded that increasing weight is strongly linked to the degree of acid exposure in the esophagus.

Diets high in volume, fat, and calories have been shown to increase esophageal acid exposure. The same dietary habits may promote both obesity and GERD.

Weight loss therapy has reduced obesity-related conditions such as diabetes and heart disease. The possibility that weight loss may also reduce complications of GERD needs to be studied.

_{Source: Ayazi S, Hagen JA, Chan LS, et al. Obesity and gastroesophageal reflux: quantifying the association between body mass index, esophageal acid exposure, and lower esophageal sphincter status in a large series of patients with reflux symptoms. J Gastrointest Surg (2009) 13:1440–1447.} 

GERD and IBS - Is There a Link?

A significant proportion of IBS patients report gastroesophageal reflux disease (GERD) symptoms, and likewise, a significant proportion of GERD patients report irritable bowel syndrome (IBS) symptoms. The reason(s) for this is unknown.

One principal theory suggests that the two common conditions overlap. This theory is supported by genetic studies and similarities in gastrointestinal sensory-motor abnormalities. The high overlap rate may be due to similar underlying GI dysfunction.

Another theory suggests that IBS-like symptoms are part of the spectrum of GERD signs and symptoms affecting different levels of the GI tract. This theory is supported primarily by studies demonstrating improvement of IBS-like symptoms in some GERD patients receiving anti-reflux treatment.

Or it may be that a recently growing interest in the full range of GERD symptoms, including those that are unusual and outside the esophagus, is leading to the recognition that lower abdominal symptoms may also be encountered in patients with GERD.

_{Source: Gasiorowska A, Poh CH, Fass R. Gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS)—is it one disease or an overlap of two disorders? Dig Dis Sci (2009) 54:1829–1834.}

Probiotics in the Treatment of IBS

A number of researchers have been looking at whether probiotics might improve symptoms of IBS. Probiotics are live micro-organisms found in foods and supplements that can have a beneficial effect.

A group of investigators conducted an independent comprehensive review of literature, published in English, reporting on randomized controlled trials that have looked at the effectiveness, safety, and tolerability of probiotics in the treatment of IBS. The review study selection criteria included randomized controls, adults diagnosed with IBS, single or combination probiotic compared to placebo, and improvement in IBS symptoms.

Of 16 randomized controlled trials that appeared to meet initial selection criteria, 11 studies were suboptimal in design (e.g., inadequate blinding, length, size). After carefully assessing the methods and designs of all the studies reviewed, only one probiotic (B. infantis 35624) showed repeated efficacy, with improvements noted in bloating, pain or discomfort, and bowel habit. However, the two studies performed with this probiotic were of short duration and longer studies are needed.

The remaining studies were limited by inadequate study design and reporting of the data.  The low quality of most of the studies made it difficult to determine whether or not other probiotics may be of clinical benefit.

The review study concluded that B. infantis 35624, based on current evidence, appears to be an effective treatment for some people with IBS. Other probiotics may prove beneficial in the future, but well designed studies are needed first.

[To find out more about probiotics (and antibiotics) in the treatment of IBS go to this IFFGD web page.]

_{Source: Brenner DM, Moeller MJ, Chey WD, Schoenfeld PS. The utility of probiotics in the treatment of irritable bowel syndrome: a systematic review. Am J Gastroenterol. 2009 Apr;104(4):1033-49.}

Do Dietary Changes Help in Coping with GI Symptoms?

Dietary changes are often considered first-line treatment in public health diseases that apply to many gastrointestinal (GI) disorders. In general, different foods and beverages may change GI motor and sensory functions, and may provoke GI symptoms. However, the role of food in functional GI disorders remains controversial. Moreover, any link between symptoms and food intake, if any, is likely to differ among persons and may vary over time for the same person.

A study by a group in Sweden looked at dietary habits and changes in food and beverage intake in relation to GI symptoms reported by identified irritable bowel syndrome (IBS) patients compared with a control population, and whether any differences between males and females were observed in these respects.

The IBS patients were recruited from Swedish primary healthcare centers on the basis of diagnoses stored in computerized medical records. A total of 515 IBS patients between the ages of 18–65 were identified during a 5-year period (1997-2001). Among the IBS patients, 14% had IBS with constipation, 31% IBS with diarrhea, and 55% mixed IBS with constipation/diarrhea. A control group of 4,500 people were randomly selected from the general population. All participants were sent a questionnaire with specific questions about self-reported food and beverage increase or decrease of GI symptoms and self-reported changes in dietary habits. Less than 1% of the study population reported lactose or gluten intolerance.

Dietary changes in general because of GI problems were reported among one-half (51%) of the female IBS patients and among nearly one-third (31%) of male IBS patients. Significantly fewer females and males in the control group reported dietary changes because of GI problems. Good or very good improvement of their GI symptoms because of dietary changes was reported by more than 1 in 3 (39%) of the female patients and 1 in 4 (24%) of the male IBS patients. Among the control group, about 1 in 10 or less (11% of females and 7% of males) reported improvement of their GI symptoms because of dietary changes.

The study concluded that female IBS patients reported more changes in their dietary habits because of their GI problems than men with IBS compared with controls. The majority of both women and men that changed their dietary habits because of GI problems reported improvement in their symptoms. Dietary advice because of functional GI problems could possibly be different for female and male IBS patients in primary care.

Several foods were reported to cause more GI complaints among both female and male IBS patients compared with the controls. These included fatty food (including fast food), certain vegetables (mainly onion, garlic, beans, peas, cabbage, pepper, or cucumber), coffee or tea, dairy products, and eggs.

[To find out more about diet and IBS go to this IFFGD web page.]

_{Source: Faresjö A, Johansson S, Faresjö T, Roos S, Hallert C. Sex differences in dietary coping with gastrointestinal symptoms. Eur J Gastroenterol Hepatol. 2009 Jun 22. [Epub ahead of print]}

5-HT Agents in the Treatment of IBS

Serotonin (5-HT) is a key modulator of gastrointestinal sensory and motor function. Many patients have IBS that can be difficult to treat, which has led to the development of newer agents, such as 5-HT3 antagonists and 5-HT4 agonists.

A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to estimate the efficacy of all available 5-HT agents in IBS. Trials recruiting adults with IBS in primary, secondary, or tertiary care comparing 5-HT3 antagonists or 5-HT4 agonists with placebo were eligible. A total of 29 RCTs were eligible for inclusion; trial quality was high.

The authors concluded that alosetron, a 5-HT3 antagonist, and tegaserod, a 5-HT4 agonist (and cilansetron, a 5-HT3 antagonist) were shown to be more effective than placebo in the treatment of IBS. Despite concerns regarding serious adverse events, which were rare in the trials identified, they are effective drugs in IBS, and their use should be considered, where availability allows, for patients who have failed conventional first- or second-line therapies.

The authors noted that while the drugs seem to have only a modest efficacy in the treatment of IBS, they may be of use in individual patients, particularly those who have failed other therapies. The risk-benefit ratio needs to be considered carefully before they are prescribed. The FDA considers the risks severe enough to require that their use be restricted. The authors compared this situation with that of NSAIDs (non-steroidal anti-inflammatory drugs), which are only modestly effective pain relievers (analgesics). The use of these agents is associated with an increased risk of heart attack (myocardial infarction), in addition to the well-established risks of GI bleeding. They stated that the absolute magnitude of the risk of serious adverse events with NSAIDs is undoubtedly higher than for 5-HT3 antagonists and 5-HT4 agonists, yet the use of NSAIDs remains entirely unrestricted, and in most countries they are freely available for purchase over-the-counter.

The application of consistent criteria to drug availability may allow a more generalized use of 5HT3 antagonists and 5HT4 agonists for IBS, as high-quality trials show that they are low risk, and are moderately effective in IBS, a disorder that is difficult to treat.

_{Source: Ford AC, Brandt LJ, Young C, Chey WD, Foxx-Orenstein AE, Moayyedi P. Efficacy of 5-HT3 antagonists and 5-HT4 agonists in irritable bowel syndrome: systematic review and meta-analysis.  Am J Gastroenterol. 2009 May 26. [Epub ahead of print]}

Understanding IBS Severity

Those affected by IBS are well aware of how severely symptoms can impact their lives. In the general community, however, IBS severity is often underappreciated. Yet treatment decisions by patients and their doctors or therapists are based on severity. Furthermore, investigators in treatment trials need to be able to measure severity when developing drugs. Lacking objective measures, severity must be based on patient experience.

The Rome Foundation and IFFGD collaborated to conduct focus groups to understand the patient’s experience of IBS and the factors that contribute to severity. Using standardized focus group assessment, this qualitative study looked at 16 participants in 3 groups with moderate to severe IBS symptoms. The groups were divided into IBS with mixed bowel patterns, IBS with diarrhea, and IBS with mixed and constipation.

In summary, pain and bowel symptoms were reported by all. Other common symptoms included bloating, nausea, and muscle pains. The participants reported disruption and restrictions on daily functioning related to symptoms. These restrictions were imposed on daily living even when the symptoms were not present due to their uncertain and unpredictable nature. Frustrations with inability to control symptoms and feelings of social isolation were common. Avoidance of activities, emotional withdrawal and fatigue were reported. Yet despite all the difficulties, most participants were optimistic that new treatments would be found. All valued peer support.

Severity was linked to health related quality of life (HRQOL). HRQOL covered a wide range of experiences, not just symptoms. The study confirms the diverse nature of IBS in terms of its symptoms and impact on patient thoughts, feelings, and behaviors. All these factors contribute to health status and illness severity regardless of the stool subtypes. These qualitative data provide a basis for assessments in larger studies.

_{Source: Drossman DA, Chang L, Schneck S, Blackman C, Norton WF, Norton NJ. A focus group assessment of patient perspectives on irritable bowel syndrome and illness severity. Dig Dis Sci. 2009 Apr 1. [Epub ahead of print]} 

Peanut butter and other peanut containing products recall

(Feb 11, 2009) Here is information provided by the U.S. Food and Drug Administration about the nationwide salmonella outbreak linked to certain peanut products. Go »

Treatment guidelines for IBS

(Dec 22, 2008) An American College of Gastroenterology (ACG) Task Force on Irritable Bowel Syndrome has completed a series of evidence-based systematic reviews of previously published studies looking at the diagnosis and treatment of irritable bowel syndrome (IBS). The resulting report, “An Evidence-Based Position Statement on the Management of Irritable Bowel Syndrome” was published in a Supplement to The American Journal of Gastroenterology, (Volume 104, Supplement 1, January 2009).

We previously reported the preliminary findings of the Task Force in the Winter 2008 issue of Digestive Health Matters.  Here, now, is a summary of highlights from the final report. 

Burden of Illness

The Task Force recognized that while IBS occurs more often in women, it is significant in men as well. Particularly, IBS is recognized to be a key component of the multi-symptom Gulf War Syndrome affecting soldiers (a predominantly male population) deployed in the 1991 Gulf War.

The Task Force reported a significant burden of illness imposed by IBS on the sufferer and on the community. Compared to patients without IBS, patients with IBS:

• visit the doctor more frequently,
• use more diagnostic tests,
• consume more medications,
• miss more workdays,
• have lower work productivity,
• are hospitalized more frequently, and
• consume more overall direct costs.

Patients with IBS have a lower health related quality of life compared with persons without IBS. The Task Force reported that in some persons, this diminished quality of life impact increases the risk of suicidal behavior.

It is important for doctors to be aware of the burden that IBS symptoms can place on patients. Bothersome symptoms that impair daily functioning need to be discussed and treated.

Diagnosis

The Statement describes IBS as a common disorder defined by abdominal pain or discomfort that occurs in association with altered bowel habits over a period of at least 3 months. No biochemical markers or structural abnormalities are present on which to make a diagnosis. Instead, there are typical symptoms on which to base the diagnosis (symptom-based criteria).

The Task Force reported that little formal testing is necessary to diagnose IBS when the symptom-based criteria are met and in the absence of “alarm” features – such as anemia, (unexplained) weight loss, and a family history of colorectal cancer, inflammatory bowel disease, or celiac sprue.

However, they noted that in IBS patients where diarrhea or mixed diarrhea/constipation is the predominant bowel symptom a blood test for celiac sprue is in order (a positive test should be confirmed by a biopsy). Celiac sprue has been seen to occur more often in persons with IBS than in otherwise healthy controls.

Treatment and Management

Recommendations in the report were graded based on a system to indicate the strength of evidence. They were classified based on:

     Each recommendation

• strong (grade 1), or
• weak (grade 2),

     Strength of evidence

• strong (level A),
• moderate (level B), or
• weak (level C).

Of interest in the review were a number of agents used to treat IBS which were shown to be more effective than placebo. Not everyone will be helped by these agents and individual responses will vary. Always be sure to ask your doctor about possible side effects, which can occur with any treatment. Here are some of the therapies included in the findings for the treatment of IBS: 

• Ispaghula husk (psyllium), a soluble fiber, is moderately more effective than placebo in improving bowel function (bran, an insoluble fiber, is no better than placebo). Bloating is a possible side effect. (Grade 2C)
• Laxatives have been studied in patients with chronic constipation, but there are no published placebo-controlled, randomized studies of laxatives in IBS.
• Certain antispasmodic agents (such as hyoscine, cimetropium, pinaverium) (Grade 2C) and some peppermint oil preparations (Grade 2B) may provide short-term relief for abdominal discomfort; data on long-term effects are lacking. [Note: Peppermint oil capsules must be swallowed whole because the raw oil can cause intense heartburn.] Much of the data is old and of poor quality. Evidence for safety and tolerability is limited.
• The antidiarrheal loperamide (e.g., Imodium, Imotil) may reduce stool frequency and improve consistency, but is no better than placebo in treating pain, bloating, or overall symptoms of IBS. There are no randomized controlled trials comparing loperamide with other antidiarrheal agents and safety and tolerability data on loperamide are lacking. (Grade 2C)  
• The gut-selective antibiotic rifaxamin (Xifaxan), currently FDA approved for the treatment of travelers’ diarrhea, may reduce overall IBS symptoms, especially bloating, with short-term dosing, although symptom recurrence is common. In 3 well-designed, randomized, placebo-controlled Phase II trials that evaluated 545 patients with IBS, rifaximin was shown to provide statistically significant improvement in overall IBS symptoms, particularly where bloating or diarrhea are the predominant bowel symptoms. There are no data available to support the long-term safety and effectiveness of rifaximin for the management of chronic IBS symptoms. Any recommendation regarding continuous or intermittent use of this agent in IBS must await further, long-term studies.  (Grade 1B)
• Probiotic products based on Bifidobacteria and certain combinations of probiotics have shown some benefit to relieve pain and bloating. Study designs had limitations and were short-term. (Grade 2C)
• Lactobacillus-based probiotics have not shown to be effective for patients with IBS.
• Alosetron (Lotronex) may reduce overall IBS symptoms when diarrhea is the predominant bowel symptom in males (Grade 2B) and females (Grade 2A). In 8 large, well-designed clinical trials that evaluated alosetron use in 4,840 patients, this drug has demonstrated superiority over placebo for abdominal pain, urgency, overall IBS symptoms, and diarrhea-related complaints. Review of the clinical and post-marketing surveillance data from IBS patients and the general population confirmed a greater incidence of severe complicated constipation and ischemic colitis in patients taking alosetron, however, the incidence of these events was low, with a rate of 1.1 cases of ischemic colitis and 0.66 cases of complicated constipation per 1,000 patients-years of alosetron use. Because of this risk, it is available to women only through a special access program. [Note: As a measure of comparison, the risk of major bleeding from taking 80 mg of aspirin per day is 1 to 2 cases per 1,000 patient-years of treatment. (Dalen, JE. Aspirin to prevent heart attack and stroke: what’s the right dose? Am J Med. 2006  Mar;119(3):198-202. )] 
• Tegaserod (Zelnorm) may reduce overall IBS symptoms in females when constipation is the predominant bowel symptom (Grade 1A) or when mixed diarrhea/constipation is the predominant bowel symptom (Grade 1B). Diarrhea is the most common side effect; and a small number (0.11%) of cardiovascular events were reported among patients who had received tegaserod in clinical trials. The drug is not available for use in North America. 
• Lubiprostone (Amitiza) in a dose of 8 mg twice daily may reduce overall IBS symptoms, especially in women when constipation is the predominant bowel symptom. The drug should not be used in patients with bowel obstruction, preexisting diarrhea, or in pregnant women and use of a contraception is advised while taking the drug. (Grade 1B)
• In the antidepressant class of drugs, selective serotonin receptor antagonists may reduce pain and overall symptoms of IBS when constipation is the predominant bowel symptom; low dose tricyclic agents may reduce pain and overall symptoms of IBS when diarrhea is the predominant bowel symptom. The use of this drug class for treatment of IBS symptoms is not linked to depression, but rather likely to effects on the brain and the gut. (Grade 1B)
• Psychological therapies, including cognitive therapy, dynamic psychotherapy, and hypnotherapy, but not relaxation therapy, are more effective than usual care in relieving overall symptoms of IBS (Grade 1B). There are no known serious adverse events associated with these therapies; however, their mechanisms of benefit remain unclear.

_{Source: Brandt L, et al. An evidence-based position statement on the management of irritable bowel syndrome: american college of gastroenterology IBS task force. Am J Gastroenterol 2008; 104: S1-S34.}

_{Top of Page}

 

The use of probiotics for GI conditions

A review of existing studies, by Kligler and Cohrssen, published by the American Academy of Family Physicians, looked at evidence for the use and effectiveness of probiotics. Probiotics are live microorganisms that benefit the health of the host when administered in adequate amounts. Several mechanisms have been proposed to explain the actions of probiotics. In most cases, it is likely that more than one mechanism is at work simultaneously.

Most of the identified benefits of probiotics relate to GI conditions.

The most consistent studies providing good-quality patient-oriented evidence found that:

• Probiotics may reduce the incidence of antibiotic-associated diarrhea, and
• Probiotics may reduce the duration and severity of acute infectious diarrhea.

Additionally the reviewers report, based on only small studies to date which provide less consistent or limited patient-oriented evidence, that:

• Probiotics (Bifidobacteria) may reduce symptoms of irritable bowel syndrome, particularly the severity of abdominal pain and bloating.

Significant adverse effects were rare. Side effects, reported now and then, included flatulence or mild abdominal discomfort. A variety of species were commonly used (including Lactobacillus sp., Bifidobacterium sp., S. thermophilus, and S. boulardii).Probiotics are generally sold as capsules, powder, tablets, liquid, or are incorporated into food. Typical dosages vary based on the product, but common dosages range from 5 to 10 billion colony-forming units (CFUs) per day for children, and from 10 to 20 billion colony-forming units per day for adults.

_{Source: Kligler B, Cohrssen A. Probiotics. Am Fam Physician. 2008;78(9):1073-1078.}

 

Do persons with diverticular disease need to avoid nuts, corn, and popcorn?

A gut diverticulum (singular) is an outpouching of the wall of the gut to form a sac. Diverticula (plural) may occur at any level from esophagus to colon. In Western societies, half the population will develop at least one, usually a few dozen diverticula, by age 60.

Uncomplicated diverticular disease is called diverticulosis and most individuals who possess colonic diverticula have no symptoms and are unaware of them. Nevertheless, colonic diverticula (one of many) can occasionally become the source of serious illness. These few may bleed or perforate thus becoming complicated diverticular disease.

Physicians usually advise individuals with diverticular disease to avoid nuts, seeds, popcorn, corn and other high-fiber foods.

Is eating nuts and other high fiber foods associated with diverticular complications? A study by Strate, et al[1] examined the association between nut, corn, and popcorn consumption and complicated diverticular disease. Information was gathered through the Health Professionals Follow-Up Study (HPFS). HPFS is sponsored by the Harvard School of Public Health and is funded by the National Heart, Lung, and Blood Institute and National Cancer Institute. The study began in 1986. The purpose of the study is to evaluate a series of hypotheses about men’s health relating nutritional factors to the incidence of serious illnesses. This all-male study is designed to complement the all-female Nurses’ Health Study, which examines similar hypotheses.

As a part of this study, men reporting newly diagnosed diverticulosis or diverticulitis were mailed supplemental questionnaires. The study included 47,228 men aged 40 to 75 years who at baseline were free of diverticulosis or its complications, cancer, and inflammatory bowel disease and returned a food frequency questionnaire. During 18 years of follow-up (1986 to 2004), there were 801 incident cases of diverticulitis and 383 incident cases of diverticular bleeding.

In this study no associations were seen between corn consumption and diverticulitis or between nut, corn, or popcorn consumption and diverticular bleeding or uncomplicated diverticulosis. In this large study of men without known diverticular disease, nut, corn, and popcorn consumption did not increase the risk of diverticulosis or diverticular complications. The authors concluded that recommendations to avoid these foods to prevent diverticular complications should be reconsidered.

[For more information about diverticulosis and diverticular disease, see IFFGD fact sheet #169, Diverticula, Diverticulosis, Diverticulitis: What’s the Difference? and fact sheet #176, Nuts, Seeds, and Diverticula.]

_{Source: [1] Strate LL, Liu YL, Syngal S, Aldoori WH, Giovannucci EL. Nut, corn and popcorn consumption and the incidenceof diverticular disease. JAMA, August 27, 2008–Vol 300, No 8;907-914.} 

 

Mycobacterium avium paratuberculosis: infrequent human pathogen or public health threat? 

People with Crohn’s disease (CD) are seven-fold more likely to have in their gut tissues the bacterium that causes a digestive-tract disease in cattle called Johne’s disease. The role this bacterium may or may not play in causing CD is a top research priority.  A report from the American Society for Microbiology (ASM) points out that the cause of Crohn’s disease is unknown, and the possible role of this bacterium, which could conceivably be passed up the food chain to people, has received too little attention from the research community. The ASM is the oldest and largest single life science membership organization in the world. To view the report Go ».

_{Source: American Academy of Microbiology (AAM) colloquia report publications (August 2008).}

Barrett's esophagus risk factors

Elucidating Risk Factors for Barrett's Esophagus

Scientists report that extra abdominal fat may be a risk factor for Barrett’s esophagus. Barrett’s esophagus is a precancerous condition where the cells lining the esophagus change in shape and organization. Short of surgical removal of the esophagus, there is no effective cure for the condition. Known risk factors for Barrett’s esophagus include being male, Caucasian, or over the age of 40. Individuals with gastroesophageal reflux disease (GERD), in which stomach acid flows backward into the esophagus, also are at increased risk of developing Barrett’s esophagus. In turn, the condition puts patients at greater risk of developing esophageal adenocarcinoma, which is rapidly increasing in the United States. Therefore, research to further understanding of the risk factors for Barrett’s esophagus may yield information that also would provide insight into the development of esophageal adenocarcinoma.

Scientists recently examined the association between obesity and abdominal girth and the occurrence of Barrett’s esophagus and GERD. Obesity is thought to be a risk factor for GERD, and extra abdominal fat could directly promote acid reflux by placing added pressure on the stomach. Obesity was determined using body mass index (BMI), a measure that takes both height and weight into account, and abdominal girth was measured simply as waist size. In this study, while there was no association of BMI with Barrett’s esophagus, larger abdominal circumference was moderately associated with the condition. The association was strongest in individuals with no GERD symptoms. When GERD symptoms were included in the analysis, the association between abdominal girth and Barrett’s esophagus was decreased, which was expected as GERD symptoms may partly mediate the effect of abdominal girth in the development of Barrett’s esophagus. These data suggest that larger abdominal girth may be a risk factor for both GERD and Barrett’s esophagus. Although the mechanism by which extra abdominal fat raises the risk of these conditions is unknown, it could act by increasing pressure on the stomach and contributing to GERD symptoms through effects on gastrointestinal mobility. The results of this research suggest that larger abdominal circumference, but not overall obesity, is a risk factor for Barrett’s esophagus. Based on these findings, reduction of waist size may be advisable for patients at high risk of developing this condition or subsequent esophageal carcinoma.

_{– Corley DA, Kubo A, Levin T, Block G, Habel L, Zhao W, Leighton P, Quesenberry C, Rumore GJ, and Buffler PA: Abdominal obesity and body mass index as risk factors for Barrett’s esophagus. Gastroenterology 133: 34-41, 2007.}

_{Source: NIDDK Recent Advances & Emerging Opportunities: Digestive Diseases and Nutrition, January 2008.}

The narcotic bowel syndrome

Narcotics are drugs, usually opiates such as morphine or oxycodone, which can relieve pain. In the U.S. narcotics are commonly prescribed for treating patients with pain, usually injuries, sudden painful conditions, or cancer. However, persons with chronic functional GI disorders should not be treated with narcotics, though this may at times be done. We are learning that under some circumstances, the use of narcotics can actually cause pain. Over time, narcotics can make nerves more sensitive, and make pain worse; they also can slow the bowel, and lead to symptoms of constipation, bloating, or nausea. This relates to the well known effects of narcotics on the bowel, opiate bowel dysfunction.

In a review article by a group from the University of North Carolina, a subset of opiate bowel dysfunction called narcotic bowel syndrome (NBS) is described. This under-recognized syndrome may be becoming more prevalent because of increasing use of narcotics for chronic painful disorders as well as lack of awareness that increased sensation to pain may be caused by long-term narcotic use. The syndrome is characterized by chronic or periodic abdominal pain that gets worse when the effect of the narcotic drug wears down. In addition to pain, which is the primary feature, other symptoms may include nausea, bloating, periodic vomiting, abdominal distension, and constipation. 

The UNC group has developed the following diagnostic criteria for narcotic bowel syndrome:

Chronic or frequently recurring abdominal pain that is treated with acute high-dose or chronic narcotics and all of the following:

• The pain worsens or incompletely resolves with continued or escalating dosages of narcotics;
• There is marked worsening of pain when the narcotic dose wanes and improvement when narcotics are re-instituted (soar and crash);
• There is a progression of the frequency, duration, and intensity of pain episodes;
• The nature and intensity of the pain is not explained by a current or previous GI diagnosis.

The key to diagnosis is the recognition that long-term or increasing dosages of narcotics lead to continued or worsening symptoms rather than benefit.

The UNC group has also developed a treatment approach. The narcotic is withdrawn and substituted with effective alternative medications to help manage the pain and the bowel symptoms until the narcotics are removed from the system. This requires the doctor and patient working closely together. The doctor must take time to explain the condition, the reasons for withdrawing the narcotics, and the alternative treatment plan. The treatment process may take several weeks or months to implement satisfactorily, with the doctor staying in touch with the patient during this period.

_{Source: Grunkemeier DMS, Cassara JE, Dalton CB, Drossman DA. The narcotic bowel syndrome: clinical features, pathophysiology, and management. Clin Gastroenterol Hepatol 2007;5:1126-1139.}

Updated guidelines for treating constipation in children

Constipation is a common pediatric problem. To assist health care professionals who care for children with constipation, the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) previously published a clinical guideline based on an integration of medical evidence with expert opinion. To evaluate studies published since then, the NASPGHAN Constipation Guideline Committee performed a comprehensive and systematic review of the medical literature since 1997, to identify, review and rate the quality of new evidence. Based on this review, the recommendations of the original clinical guideline were reaffirmed with several modified according to the new evidence. Among the updates reported: 

1. There are conflicting reports on the value of fiber for constipated children. Some studies find that constipated children are consuming less fiber than unaffected children; other studies find constipated children are consuming more fiber; and still others find no difference. The society recommends that further studies are needed before it can make a recommendation one way or the other.
2. Polyethylene glycol 3350 (PEG 3350) is an osmotic laxative which has been found to help disimpaction in constipated children. However, before it can recommend this laxative for use in babies the society recommends further safety studies.
3. The society has reviewed studies looking at biofeedback to help improve symptoms of constipation in children. No study showed long-term improvement; however, short-term improvements (about three months in length) were seen. The society recommends that biofeedback therapy can be an effective short-term treatment in some patients.
4. Studies looking at the effect of cow’s milk in the diet show mixed results. The society recommends that in children whose constipation does not improve on standard medical and behavioral management, it is worth considering a short trial of a cow’s milk-free diet to see if symptoms improve.  

Does allergy play a role in irritable bowel syndrome (IBS) and in constipation? 

There is a common belief that allergy contributes to constipation or irritable bowel syndrome (IBS) with symptoms of constipation. However, reports have not been able to conclusively show that restricting allergens from a diet improves IBS or constipation symptoms. This study from Italy of children aged 3–13 years tried to find an answer looking in the other direction, by looking at whether children with demonstrated allergies – such as asthma, eczema, or food allergy – are more prone to have constipation or IBS. A group 196 children with allergic symptoms were enrolled and compared to a second group 127 nonallergic children as controls. Both groups were tested for allergies to a wide range of common food and other allergens, using a rigorous test called a skin prick test (SPT). Using a symptom questionnaire based on the Rome criteria for functional gastrointestinal disorders, the occurrence of constipation was found to be similar in both groups. IBS was found in 6.6% of the allergic children and in 6.3% of the nonallergic controls.   

The study found that allergic children were not more likely than nonallergic children to have IBS or constipation symptoms. It was found that children who had at least one SPT allergic reaction to a food item were more likely to have IBS than children with no reaction to the food SPTs. The study concludes that children with allergies do not need to fear increased chances of developing IBS, but if they have positive SPT tests to food, they should also be examined for the presence of IBS symptoms.

_{Source: Caffarelli C, Coscia A, Baldi F, Borghi A, Capra L, Cazzato S, Migliozzi L, Pecorari L, Valenti A, Cavagni G. Characterization of irritable bowel syndrome and constipation in children with allergic diseases. Eur J Pediatr. 2007 Mar 8; [Epub ahead of print]}

How common is food allergy in children?

This study from Brazil reviewed current research (2000–2006) on food allergies in children. Their primary conclusion is that food allergies are very often over-diagnosed. Other specific findings include: 

• Diagnoses of allergic diseases, and especially allergies to food, have increased in the last 20 years or so.
• Children are much more likely to be diagnosed as having food allergies than adults.
• Food intolerance is often mistaken for food allergy. Food intolerance occurs when the body cannot adequately digest a portion of a particular food. Food allergy is an immune system response where the body creates antibodies as a reaction to certain food.  
• Patients and their families are known to overestimate their own food allergies. In one study of 500 newborn babies, 28% of them were thought to have food allergies by their parents. However, a rigorous test for food allergies found that only 6% had a reaction to the suspect food. 
• Elimination diets (a doctor-supervised diet in which a specific food or ingredients is removed from the diet to test whether symptoms disappear in the absence of the suspect food item) is not always a reliable test for true food allergy. The recommended diagnostic procedure is skin testing followed by IgE antibody testing.
• Currently, the only strategy for managing a food allergy is a diet with total elimination of the offending food item. To prevent malnutrition or other ill effects, these diets must be supervised by a physician.
• Most parents are unable to identify common allergic food ingredients on product labels, so any restrictive diet should be accompanied by extensive education about dietary management needs.
• Cow’s milk allergy usually goes away within the first three years of life in most patients.

While soy-based formulas have been successfully used to treat babies with demonstrated food allergies or food intolerance, there is no basis for recommending soy formula as a way to prevent food allergies.      

_{Source: Ferreira CT, Seidman E. Food allergy: a practical update from the gastroenterological viewpoint. J Pediatr (Rio J). 2007 Jan-Feb;83(1):7-20.}

 

Do infants with GERD become adults with GERD?

It is commonly accepted that reflux symptoms will usually resolve during the first year or two of life. Data collected over a one-year period in 19 infants assigned to a placebo group as part of a placebo-controlled drug treatment study of 100 infants total was looked at. It was found that symptoms resolved in more than one-half of those in the placebo assigned group. However, the study also found that microscopic inflammation might continue to be present in the esophagus even after symptoms appear to be gone.

This raises a question. Are these individuals at risk for later problems? The results of this study call attention to the need for better understanding about GERD in infancy and childhood including screening and treatment approaches.

_{Source: Orenstein SR, Shalaby TM, Kelsey SF, Frankel E. Natural history of infant reflux esophagitis: symptoms and morphometric histology during one year without pharmacotherapy. Am J Gastroenterol. 2006 Mar;101(3):628-40.}

Do genetic or environmental factors contribute to irritable bowel syndrome (IBS)?

A study looked at 12,700 Norwegian twins born between 1967 and 1979. It found that both genetic and external factors may contribute to IBS. Identical twins share exactly the same genes. Non-identical twins share 50% of the same genes. The identical twins were more likely to develop IBS due to external factors, such as low birth rate, as well as due to the influence of genetic makeup.

_{Source: Bengtson MB, Ronning T, Vatn M, Harris J. IBS in twins: genes and environment. Gut. 2006 Dec;55(12):1694-1946.}

How does the patient-doctor relationship help treat IBS?

In a Mexico City study of 55 patients seeing a doctor in a specialty referral clinic for the first time, 4 factors were looked at in relation to their seeking health care:

• abdominal pain/discomfort
• fear of cancer
• impairment in daily function
• symptom stressfulness

Of these, pain/discomfort and symptom stressfulness were the most important factors that drove the patients to seek care. Feelings of anxiety, depression, and quality of life impairment arising from cancer fear, daily function impairment, and stress from symptoms were present.

Patients want to talk about and to be given information about their disease. A thorough explanation of the disease and reassurance from the doctor decreased the self-perception of impairment in daily function and cancer fear.

_{Source: Schmulson M, Oritz-Garrido O, Hinojosa C, Arcila D. A single session of reassurance can acutely improve the self-perception of impairment in patients with IBS. Journal of Psychosomatic Research 2006;61:461-467.}

Is childhood GERD a risk factor for adult symptoms?

A study in Texas examined the prevalence and risk factors for current gastroesophageal reflux disease (GERD) symptoms in 113 young adults (mean age 18 years) with a history of childhood GERD (mean age at the time of childhood diagnosis was 10 years). Almost half of the young adults with a history of GERD as children reported that they currently suffer from heartburn and reflux symptoms a minimum of once every week with most of these taking medications to control their symptoms.

The study cautions that the prevalence of GERD found in this group is considerably higher than previously found in a group of this age. Nevertheless, they conclude that childhood GERD should be considered a risk factor for adolescent and adult GERD.

_{Source: El-Serag HB, Richardson P, Pilgrim P, Gilger MA. Determinants of gastroesophageal reflux disease in adults with a history of childhood gastroesophageal reflux disease Clin Gastroenterol Hepatol 2007 Jun;5(6):696-701.}

 

Is there a relationship between IBS, dyspepsia, and quality of life in GERD sufferers? 

Numerous studies show patients diagnosed with GERD are more likely than others to also suffer from irritable bowel syndrome (IBS) or functional dyspepsia (pain or discomfort in the upper abdominal area). A recent study in The Netherlands confirmed this and examined health-related quality of life in these individuals. In patients with GERD (confirmed through a 24-hour pH monitoring test that measures reflux), 25% had dyspepsia, 35% had IBS, and 5% had both. Only 35% had neither IBS nor dyspepsia.

Researchers used a questionnaire with 9 subscales to measure health-related quality of life (HRQoL) in the study participants. Patients who had only GERD had lower scores on 1 of the 9 subscales. GERD patients who also had functional dyspepsia had lower scores on 6 subscales. GERD patients with IBS scored lower on 8 subscales. Patients with GERD, IBS, and functional dyspepsia scored lower on 7 subscales.

The study concluded that in patients with proven GERD, functional dyspepsia and IBS are more prevalent than in the general population; and this prevalence is higher among care-seeking GERD patients. Those GERD patients who also have functional dyspepsia and/or IBS have a much lower HRQoL, suggesting that when GERD is properly treated, health related quality of life is affected mainly by coexisting functional disorders and not by GERD itself.

_{Source: De Vries DR, Van Herwaarden MA, Baron A, Smout AJ, Samsom M. Concomitant functional dyspepsia and irritable bowel syndrome decrease health-related quality of life in gastroesophageal reflux disease Scand J Gastroenterol 2007 Aug;42(8):951-6.}