De-novo Inflammatory Bowel Disease After Bariatric Surgery: A Large Case Series

Case reports of inflammatory bowel diseases [IBD] have been reported in patients with a history of bariatric surgery. Our aim was to characterize patients who were diagnosed with IBD after having undergone bariatric surgery.

Electronic medical records were reviewed at two institutions to identify patients who developed de-novo Crohn's disease or ulcerative colitis [UC] after bariatric surgery. Data on demographics, type of bariatric surgical procedure, IBD subtype, phenotype and medication usage were obtained. The incidence rate of de-novo IBD after bariatric surgery [per 100000 person-years] and standardized incidence ratio [SIR] were estimated from a prospective bariatric surgery database.

A total of 44 patients with de-novo IBD after bariatric surgery were identified [31 Crohn's disease, 12 UC, one IBD unclassified]. Most patients were female [88.6%], with median age at IBD onset of 44 years [IQR, 37-52] and median time to IBD diagnosis after bariatric surgery of 7 years [IQR, 3-10]. Sixty-eight per cent underwent Roux-en-Y gastric bypass. In the prospective database, the incidence of IBD in patients who underwent bariatric surgery was 26.7 per 100000 person-years [4.5 for UC and 22.3 for Crohn's disease]. The age-adjusted SIR ranged from 3.56 in the 40-49 year age group to 4.73 in the 30-39 year age group.

We described a case series of patients developing de-novo IBD after bariatric surgery. There appears to be a numerically higher incidence of Crohn's disease in this population. Confirmation of causality is required in larger patient cohorts.