Risk factors for upper and lower functional gastrointestinal disorders in Persian Gulf War Veterans during and post-deployment.

Background Gastroenteritis is a risk factor for irritable bowel syndrome (IBS), but its role in other functional gastrointestinal disorders (FGIDs) is less clear. The aim of this study was to determine the prevalence of FGIDs in Gulf War (GW) Veterans before, during, and after deployment and to determine whether gastroenteritis was a risk factor for upper and lower FGIDs. Methods The Veterans who served during the Persian GW were mailed validated questionnaires inquiring about their bowel habits, psychological and extra-intestinal symptoms, and quality of life (QOL). The lactulose hydrogen breath test (LBT) was performed for small intestinal bacterial overgrowth. Key Results Data were analyzed from 468 GW Veterans. The prevalence of FGID before, during, and 16 years after deployment was 15.7%, 49.9%, and 64.2%, respectively. New FGIDs during deployment was reported by 41.2%, and during 16 years after deployment, 43.7% acquired new FGIDs. FGIDs were associated with psychological disorders, extra-intestinal symptoms, and lower QOL. Gastroenteritis was reported by 44.3% of deployed Veterans and was a risk factor for IBS, dyspepsia, and functional diarrhea post-deployment. The cases and controls did not differ significantly in the frequency of positive LBT. Conclusions and Inferences There is an increase in the prevalence of FGIDs during deployment, and it persists after deployment. There is a further increase in the prevalence of FGIDs after deployment. In addition to IBS, gastroenteritis during deployment is a risk factor for dyspepsia and functional diarrhea post-deployment. Therefore, prevention of gastroenteritis during deployment and screening of Veterans for FGIDs post-deployment would be of value for Veterans' long-term health.