Regardless, there is still no clear-cut explanation why bariatric surgery would cause IBD. One of the proposed mechanisms is vitamin D deficiency caused by malabsorption, a common consequence of the Roux-en-Y procedure. Vitamin D deficiency is often linked with an increased risk of developing IBD. Additionally, bariatric surgery may alter bile acid composition, which can have inflammatory effects.
Because no direct mechanism has been identified, Dr. Ungaro stated that further research needs to be done.
“The potential association between prior bariatric surgery and new IBD highlights the need to perform a thorough work-up and have a broad differential diagnosis in postbariatric surgery patients with new gastrointestinal symptoms,” Dr. Ungaro and his colleagues wrote. “However, given the nature of administrative database studies, we cannot draw causative conclusions and further prospective studies are needed to confirm this association and delineate if certain types of bariatric surgeries have differential effects on risk of IBD.”
Multiple authors who worked on this study have worked as consultants for pharmaceutical companies. Dr. Ungaro is supported by a Crohn’s and Colitis Foundation career development award and a KL2 Scholar award.
SOURCE: Ungaro R et al. Aliment Pharmacol Ther. 2018 Mar 7;47[8]:1126-34: doi: 10.1111/apt.14569.