Gastrointestinal function and eating behavior after gastric bypass and duodenal switch

Duodenal switch provides greater weight loss than gastric bypass in severely obese patients; however, comparative data on the changes in gastrointestinal symptoms, bowel function, eating behavior, dietary intake, and psychosocial functioning are limited.

The setting for the present study was 2 university hospitals in Norway and Sweden. Participants with a body mass index of 50-60 kg/m(2) were randomly assigned to gastric bypass (n = 31) or duodenal switch (n = 29) and followed up for 2 years. Of the 60 patients, 97% completed the study. Their mean weight decreased by 31.2% after gastric bypass and 44.8% after duodenal switch. At inclusion and 1 and 2 years of follow-up, the participants completed the Gastrointestinal Symptom Rating Scale, a bowel function questionnaire, the Three-Factor Eating Questionnaire-R21, a 4-day food record, and the Obesity-related Problems scale.

Compared with the gastric bypass group, the duodenal switch group reported more symptoms of diarrhea (P = .0002), a greater mean number of daytime defecations (P = .007), and more anal leakage of stool (50% versus 18% of participants, respectively; P = .015) after 2 years. The scores for uncontrolled and emotional eating were significantly and similarly reduced after both operations. The mean total caloric intake and intake of fat and carbohydrates were significantly reduced in both groups. Protein intake was significantly reduced only after gastric bypass (P = .008, between-group comparison). Psychosocial function was significantly improved after both operations (P = .23, between the 2 groups).

Gastrointestinal side effects and anal leakage of stool were more pronounced after duodenal switch than after gastric bypass. Both procedures led to reduced uncontrolled and emotional eating, reduced caloric intake, and improved psychosocial functioning.