OBJECTIVE: Adverse early life events are key factors for development of functional gastrointestinal disorders (FGIDs). Urinary tract infection (UTI) is associated with chronic pelvic pain in adults, a finding that has been recapitulated in murine models, but the relation between UTI and chronic pelvic and abdominal pain has not been studied in children. We hypothesized that UTI in infancy increases the risk of FGIDs and chronic abdominal pain (CAP) in childhood. METHODS: The present study included children, ages 4 to 18 years, with a single UTI in the first year of life and their siblings with no history of UTI. Parents completed the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III Version (QPGS-III) by telephone. Children meeting QPGS-III criteria for FGIDs but with pain less than once weekly were considered to have CAP. RESULTS: A total of 57 patients with UTI and 58 sibling controls were identified. Mean age at UTI was 4.8 months, and mean time since UTI was 9.3 years. At the time of survey, mean age of patients was 9.7 years (5-16 years, 40% boys) and that of controls was 9.6 years (range 4-17 years, 57% boys). FGIDs were diagnosed in 6 of 57 (11%) patients, and 1 of 58 (2%) controls (P = 0.06). CAP was identified in 10 of 57 (18%) patients and 2 of 58 (3%) controls (P = 0.02). Predominant sex (female), infecting organism (E coli), and treatment (third-generation cephalosporin) were similar in patients with UTI with and without CAP. CONCLUSIONS: We show for the first time that UTI is associated with CAP in childhood. We speculate that pelvic organ sensory convergence explains our findings.