The incidence and gastrointestinal infectious risk of functional gastrointestinal disorders in a healthy US adult population

Objectives: Functional gastrointestinal disorders (FGDs) are recognized sequelae of infectious gastroenteritis (IGE). Within the active duty military population, a group with known high IGE rates, the population-based incidence, risk factors, and attributable burden of care referable to FGD after IGE are poorly defined. Methods: Using electronic medical encounter data (1999-2007) on active duty US military, a matched, case-control study describing the epidemiology and risk determinants of FGD (irritable bowel syndrome (IBS), functional constipation (FC), functional diarrhea (FD), dyspepsia (D)) was conducted. Incidence rates and duration of FGD-related medical care were estimated, and conditional logistic regression was utilized to evaluate FGD risk after IGE. Results: A total of 31,866 cases of FGD identified were distributed as follows: FC 55% (n=17,538), D 21.2% (n=6,750), FD 2.1% (n=674), IBS 28.5% (n=9,091). Previous IGE episodes were distributed as follows: specific bacterial pathogen (n=65, 1.2%), bacterial, with no pathogen specified (n=2155, 38.9%), protozoal (n=38, 0.7%), viral (n=3431, 61.9%). A significant association between IGE and all FGD (odds ratio (OR) 2.64; P<0.001) was seen, with highest risk for FD (OR 6.28, P<0.001) and IBS (OR 3.72, P<0.001), and moderate risk for FC (2.15, P<0.001) and D (OR 2.39, P<0.001). Risk generally increased with temporal proximity to, and bacterial etiology of, exposure. Duration of FGD-related care was prolonged with 22.7% having FGD-associated medical encounters 5 years after diagnosis. Conclusions: FGD are common in this population at high risk for IGE. When considering effective countermeasures and mitigation strategies, attention directed toward prevention as well as the acute and chronic sequelae of these infections is needed.