Review Article

The Relationship Between Obesity, Bariatric Surgery, and Inflammatory Bowel Disease

Fiorella Cañete; Míriam Mañosa; Ariadna Clos; Eduard Cabré; Eugeni Domènech


Aliment Pharmacol Ther. 2018;48(8):807-816. 

In This Article

Bariatric Surgery in Patients With IBD

Recently, two retrospective studies that assessed perioperative outcomes of bariatric surgery in IBD patients using the largest all-payer in-patients database in the United States were published (Table 2). The first study, based on the data from the Nationwide Inpatient Sample[46] in the United States between 2011 and 2013, evaluated the safety of bariatric surgery in patients with IBD.[47] From a total of 314 864 adults who underwent bariatric surgery, 790 had underlying IBD (459 with CD and 331 with UC) and the remaining non-IBD patients constituted the control group. Regarding complications after bariatric surgery, there was only a significant increase in small bowel obstruction in the IBD group (and also when analysed exclusively in CD or in UC), without significant differences in other bariatric surgery related complications (gastrointestinal bleed, infection, dehiscence or reoperation). Although this study is of great relevance for the safety evaluation of bariatric surgery in IBD patients, several limitations have to be taken into account. First, data on BMI were not provided and the percentage of IBD patients with morbid obesity undergoing bariatric surgery is therefore unknown. Second, the type of bariatric surgery procedure is not detailed. Finally, the clinical characteristics of IBD are not provided and, therefore, the proportion of active smokers, patients with penetrating or stricturing behaviour, or perianal disease, is unknown. Nonetheless, the authors conclude that bariatric surgery is a safe and feasible procedure to perform on IBD patients, especially those who are at higher risk of cardiovascular morbidity and in drastic need of weight reduction.

The second study,[48] performed on a cohort of patients from the same database (the United States National Inpatient Sample database), included all in-patients between 2004 and 2014 with morbid obesity and IBD. Among them, hospitalisations with prior bariatric surgery (Roux-en-Y gastric bypass, gastric band, and sleeve gastrectomy) were identified. Among 15 319 patients with IBD and morbid obesity at discharge, 493 patients (3.2%) had previous bariatric surgery. The mean age was 46 years, with a higher prevalence of Caucasian (82.2%) and female (84.2%) patients. Almost half of the patients had a history of arterial hypertension. With regard to the type of bariatric surgery, 48% of the patients underwent sleeve gastrectomy, 35% Roux-en-Y gastric bypass and 17% gastric banding. It is noteworthy that, in the multivariable analysis, IBD patients with a history of bariatric surgery had a similar mortality rate and a decreased risk of renal failure, under-nutrition, and fistulae formation when compared to morbidly obese IBD patients without bariatric surgery. From these results, bariatric surgery appears to reduce morbidity in obese patients with IBD, which means that IBD does not appear to be a contraindication for weight loss surgery.

Beyond these two large studies, we aimed to further evaluate the phenotypic and clinical characteristics of IBD patients undergoing bariatric surgery, as well as its impact on the course and therapeutic requirements of IBD. Table 2 summarises the current evidence based on a few case reports, one retrospective case-control study, one prospective case-control study and two population-based studies, describing a total of 42 patients (24 with CD and 18 with UC) in which clinical and therapeutic features and clinical outcomes of IBD were described[10,49–53]

CD Patients Undergoing Bariatric Surgery

Four studies reported the clinical features, post-operative complications and clinical outcomes of a total of 24 CD patients who underwent bariatric surgery, summarised in Table 3 (detailed information in Table S3a).[10,51–53] The mean age of the patients was 43 years and the mean IBD duration was 16 years (reported only in three and two studies, respectively). Disease location was only available for 16 patients, ileocolonic being the most frequent (44%). Disease behaviour was described in nine cases (44% inflammatory, 44% structuring and 12% penetrating). Two studies reported the previous performance of IBD-related surgery: two ileocecal resections and two patients with total proctocolectomy. No information about perianal disease and smoking habits was provided in any of the studies. The bariatric procedures were sleeve gastrectomy in 19 patients, three cases of laparoscopic adjustable gastric banding (one with conversion into Roux-en-Y gastric bypass) and one of Maclean gastroplasty. Of note, three patients underwent proctocolectomy prior to bariatric surgery[52] and two patients had fibrostenotic disease of the terminal ileum that was treated by minimal ileocecal resection concomitant to bariatric procedure.[53]

Post-operative complications and CD outcomes after bariatric surgery are also summarised in Table 3 and Table S3a. Overall, there were very few post-operative complications, and all authors concluded that bariatric surgery is a safe procedure in CD patients. Bariatric surgery was considered to be efficient and no cases of malnutrition or excess weight loss were reported. Furthermore, CD did not worsen clinically in most patients, with only one requiring biological therapy soon after bariatric surgery.

UC Patients Undergoing Bariatric Surgery

Only five studies[49–53] of bariatric surgery in morbidly obese patients with UC have been published, including a total of 18 patients, summarised in Table 4 (detailed information in Table S4a). However, baseline characteristics, age, comorbidities, UC duration and previous UC-related surgery were reported, though scantily, for five patients. UC extent was available for only three patients, and no information about smoking habit was reported for any patient. Regarding bariatric procedure, in contrast to CD patients, there was a greater number of Roux-en-Y gastric bypass (8 patients), followed by sleeve gastrectomy in eight additional patients, and only one laparoscopic adjustable gastric banding and one biliopancreatic derivation.

Post-operative complications and UC outcomes after bariatric surgery are summarised in Table 4 and Table S4a. Interestingly, acute flare-ups occurred in two of 18 patients early after surgery, with all the remaining patients but one following a stable course of the disease. It is also important to highlight that one patient developed severe protein malnutrition after a biliopancreatic derivation. No other relevant complications were reported.