This trial is active, not recruiting.

Conditions irritable bowel syndrome, small intestinal bacterial overgrowth
Treatments placebo, rifaximin
Sponsor Department of Veterans Affairs
Start date October 2007
End date October 2008
Trial size 140 participants
Trial identifier NCT00680836, GWRA-014-05F


The purposes of this study are to estimate the burden of disease due to chronic gastrointestinal illness in PG veterans, to evaluate whether SBBO is associated with chronic diarrhea in PG veterans, and to determine whether eradication of SBBO reduces symptoms of chronic diarrhea, abdominal pain and bloating in PG veterans.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Allocation randomized
Endpoint classification efficacy study
Intervention model parallel assignment
Masking double blind (subject, investigator, outcomes assessor)
Primary purpose treatment
(No Intervention)
These patients do not have IBS. They may be deployed or non-deployed veterans.
(Active Comparator)
These patients have IBS and are receiving the rifaximin.
550 mg orally two times per day for 14 days
(Placebo Comparator)
These patients have IBS and are receiving the placebo.
orally two times per day for 14 days

Primary Outcomes

Improvement in IBS Global Improvement Scale.
time frame: once a month for the 6 months following completion of medication

Secondary Outcomes

Change in Symptom Severity
time frame: 6 months after medication regimen is completed
Change in IBS-QOL Questionnaire
time frame: 1 week after starting the medication, 2 weeks after starting the medication, 1 month after finishing medication, 6 months after finishing medication
Change in LBT
time frame: 6 months after completion of medication

Eligibility Criteria

Male or female participants from 35 years up to 72 years old.

Inclusion Criteria: - Men and women age 32-75 years - Rome III criteria for diarrhea-predominant IBS - Symptom onset after an apparent episode of acute gastroenteritis - Symptoms of > 3 months duration - Normal endoscopic appearance of the colonic mucosa - Negative markers for celiac disease and inflammatory bowel disease. - Normal thyroid function and serum calcium levels. - Must have served in the military or reserves during the time of Operation Desert Storm (August 1990 to May 1991) Exclusion Criteria: - Clinically significant cardiac, pulmonary, hepatic or renal dysfunction - History of/or presence of systemic malignancy - Current evidence of any gastrointestinal disorder such as celiac disease or inflammatory bowel disease (i.e. Crohns disease or ulcerative colitis) - Current effects of drug or alcohol abuse - Investigator perception of patients inability to comply with study protocol - Unstable psychiatric disease - Recent change in gastrointestinal medications - Subjects with a positive pregnancy test - Subject is currently participating in another research protocol that could interfere or influence the outcome measures of the present study

Additional Information

Official title Diarrhea-Predominant Irritable Bowel Syndrome in Persian Gulf Veterans
Principal investigator Ashok K Tuteja, MD MPH
Description Approximately 700,000 United States military personnel were deployed in the first Persian Gulf (PG) War. Several months after their return, up to 25% of Veterans had persistent symptoms which they suspected were related to their military service in the Gulf. Among the most frequent were gastrointestinal symptoms such as loose stools, excessive gas and abdominal pain. These symptoms are typical of diarrhea-predominant irritable bowel syndrome (IBS). The cause of IBS is not known; speculated mechanisms include altered GI motility, bacterial overgrowth, visceral hypersensitivity and psychological stress. Another proposed mechanism relates to the fact that up to one third of patients with IBS describe the onset of their symptoms following acute gastroenteritis. This is called post-infective IBS (PI-IBS). How acute gastroenteritis leads to persistent GI symptoms of IBS is not known. A limited amount of data suggests that patients with IBS may have an imbalance in their gastrointestinal microflora. Several studies indicate that small bowel bacterial overgrowth is more common in individuals with IBS. Symptoms of SBBO are similar to diarrhea-predominant IBS and include chronic diarrhea, bloating and abdominal pain. More than 50 percent of military personnel developed acute gastroenteritis while on duty in the Gulf. Most of them who reported symptoms of IBS had an acute onset which occurred in association with an episode of acute gastroenteritis during their tour of duty. Other travelers are known to be colonized by new micro-organisms during travel to foreign countries. This acquisition is thought to be related to a change in diet. The natural history of this change in bowel flora, in part, depends on host factors and can persist for months after travel abroad. It seems likely, that PG veterans with persistent diarrhea and a negative work-up for known GI diseases have PI-IBS. No study in the past has evaluated the role of SBBO in causing chronic GI symptoms in PG Veterans. Furthermore, soldiers involved in combat are exposed to a highly stressful environment, perhaps making them more susceptible to persistent symptoms. We hypothesize that PG veterans with chronic GI symptoms have symptoms of diarrhea predominant IBS and this is caused by SBBO due to a change in microflora during deployment in the Persian Gulf and that it is predisposed to by the stress of combat. Intestinal microflora, once altered, is known to be relatively stable; once mucosal damage occurs it may become permanent. Objectives Objective # 1: Estimate the burden of disease due to chronic gastrointestinal illness in PG veterans. Hypothesis: i. The prevalence of GI symptoms is high in PG veterans. ii. The prevalence of IBS is higher in veterans who report acute gastroenteritis during the period of deployment. iii. PG Veterans with IBS have a lower IBS related QOL Objective # 2: Evaluate whether SBBO is associated with chronic diarrhea in PG veterans. Hypothesis i. SBBO is more common in PG veterans than non deployed veterans. ii. SBBO is more common in PG veterans with diarrhea-predominant IBS vs. those without. Objective: # 3: Determine whether eradication of SBBO reduces symptoms of chronic diarrhea, abdominal pain and bloating in PG Veterans. Hypothesis: i. Treatment with rifaximin, a non-absorbable antibiotic, will improve symptoms and QOL in Veterans with SBBO.
Trial information was received from ClinicalTrials.gov and was last updated in August 2013.
Information provided to ClinicalTrials.gov by Department of Veterans Affairs.