Researchers tracked 249 extremely obese patients who had a common type of weight-loss surgery known as Roux-en-Y Gastric Bypass, which reduces the size of the stomach to the size of an egg.
Roux-en-Y surgery involves attaching the stomach pouch directly to the small intestine, bypassing most of the stomach and the upper part of the intestine. It reduces the amount of food a person can eat.
Two years after surgery, patients lost an average of 31% of their body weight. The bad news is they were significantly more likely to have digestive problems than 295 obese people who did not have surgery.
The most common gastrointestinal problems were indigestion, flatulence, belching, gurgling, and hard or loose stools.
Around 71% of gastric bypass surgery patients experienced food intolerance, compared to 17% of the non-surgery group.
The most common problematic foods were fried food (30%), carbonated drinks (28%), and cakes/pies/pastries (23%). About one in five patients could not eat red meat, chocolate, or whipped cream.
Of particular concern was that 8% of patients reported intolerance to water. About 14% said the intolerance was “very bothersome,” and half could not eat at least four types of food.
“We were a little surprised that flatulence is such a big problem,” said Dr. Thomas Boerlag, lead author of the study. “In most cases the health benefits outweigh the side effects by far. However, it helps them to better inform their patients about what to expect after surgery.”
Source: Gastrointestinal symptoms and food intolerance 2 years after laparoscopic Roux-en-Y gastric bypass for morbid obesity — British Journal of Surgery (December 2016)