Laparoscopic gastric bypass is an effective treatment for obesity, but a new study finds that patients who undergo the surgery often complain of gastrointestinal problems.

The study included 249 obese patients who underwent the surgery and 295 obese controls, all of whom completed a questionnaire. Surgical patients completed the questionnaire two years after surgery.

Surgical patients often experienced indigestion. Also, food intolerance, especially for food with a high fat or sugar content and for red meat, was a common side-effect of the surgery: food intolerance for specific products was reported by 70.7 per cent of postoperative patients compared with 16.9 percent of controls.

"Most studies in weight loss surgery focus on the short-term effects of surgery, and there was limited knowledge about the effect of a gastric bypass on gastrointestinal complaints in the long term," said Dr. Thomas Boerlage, lead author of the British Journal of Surgery study. "With this study, physicians can better counsel their patients, both before and after surgery. It also helps patients considering a gastric bypass to make a more well-thought decision.

Article: Gastrointestinal symptoms and food intolerance 2 years after laparoscopic Roux-en-Y gastric bypass for morbid obesity, T. C. C. Boerlage, A. W. J. M. van de Laar, S. Westerlaken, V. E. A. Gerdes and D. P. M. Brandjes, British Journal of Surgery, doi: 10.1002/bjs.10419, published online 19 December 2016.