Donnachie E, et al. - This population-level study aimed to examine the occurrence of postinfectious irritable bowel syndrome (IBS) in routine outpatient care, comparing different types of GI infection and its interaction with psychosomatic comorbidity. For IBS, psychological disorder and GI infections were distinct risk factors. The high incidence of non-specific GI infection recommended that in primary care, post-infectious IBS was a common clinical occurrence. Chronic fatigue was a further significant sequela of GI infection.

• The authors performed this retrospective cohort study using routinely collected claims data covering statutorily insured patients in Bavaria, Germany.
• They defined cases as patients without prior record of functional intestinal disorder with a first-time diagnosis of GI infection between January 2005 and December 2013 and classed according to the type of infection.
• They matched each case by age, sex and district of residence to a patient without history of GI infection.
• They evaluated prior psychological disorder (depression, anxiety or stress reaction disorder) in the 2 years prior to inclusion.
• They used proportional hazards regression models to estimate the HRs for GI infection and psychological disorder.
• They assessed chronic fatigue syndrome (CFS) as a comparator outcome.

• The authors identified 508278 patients with first diagnosis of GI infection, resulting in a matched cohort of 1 016 556 patients.
• All infection types were correlated with an increased risk of IBS (HR: 2.19-4.25) and CFS (HR 1.35-1.82).
• For IBS (HR: 1.73) and CFS (HR: 2.08), prior psychological disorder was a distinct risk factor.
• For both conditions, female sex was a further risk factor.