Bariatric Surgery Is Associated With Increased Risk of New–onset Inflammatory Bowel Disease

Case Series and National Database Study

R. Ungaro; R. Fausel; H. L. Chang; S. Chang; L. A. Chen; A. Nakad; A. El Nawar; I. Prytz Berset; J. Axelrad; G. Lawlor; A. Atreja; L. Roque Ramos; J. Torres; J.-F. Colombel


Aliment Pharmacol Ther. 2018;47(8):1126-1134. 

In This Article

Abstract and Introduction


Background Case series suggest a possible association between bariatric surgery and incident IBD.

Aim The aim of this study was to evaluate the association between bariatric surgery and new–onset IBD.

Methods We first conducted a multi–institutional case series of patients with a history of IBD and bariatric surgery. We next conducted a matched case–control study using medical and pharmacy claims from 2008 to 2012 in a US national database from Source Healthcare Analytics LLC. Bariatric surgery was defined by ICD–9 or CPT code. Bariatric surgery was evaluated as recent (code in database timeframe), past (past history V code) or no history. Conditional logistic regression was used to estimate odds ratios (OR) and 95% CI for new–onset IBD, CD and UC.

Results A total of 15 cases of IBD (10 CD, 4 UC, 1 IBD, type unclassified) with a prior history of bariatric surgery were identified. Most cases were women, had Roux–en–Y surgery years prior to diagnosis and few IBD–related complications. A total of 8980 cases and 43 059 controls were included in our database analysis. Adjusting for confounders, a past history of bariatric surgery was associated with an increased risk of new–onset IBD (OR 1.93, 95% CI 1.34–2.79). However, patients who had recent bariatric surgery did not appear to be at shorter term risk of IBD (OR 0.94, 95% CI 0.58–1.52).

Conclusion New–onset IBD was significantly associated with a past history of bariatric surgery. This potential association needs to be confirmed in future prospective studies.


The incidence of IBD is rising worldwide.[1] Although genetics and an aberrant immune response are central in IBD pathogenesis, environmental factors also play a key role. Prior research has highlighted the importance of risk factors such as smoking, medication exposures, diet and vitamin D.[2–7] One environmental factor that can affect the likelihood of developing IBD is surgery. Appendectomy may increase the risk of CD and appears to have a protective effect against the development of ulcerative colitis (UC) although this effect in UC has been questioned.[8,9] Recently, there have been case reports of patients developing CD following bariatric surgery.[10–14] Interestingly, there have also been reports of immune–mediated diseases occurring after weight loss surgery.[15] In order to explore the possible relationship between bariatric surgery and IBD, we first compiled a multicentre descriptive case series. We subsequently examined the association between prior bariatric surgery and risk of new–onset IBD in a large health claims database.