(HealthDay)—While weight-loss surgery can help obese people drop unwanted pounds, a new study suggests the procedure may also trigger long-lasting tummy troubles for many patients.
Dutch researchers found that people who had the most common type of weight-loss surgery—known as laparoscopic Roux-en-Y gastric bypass—suffered gastrointestinal problems and food intolerance up to two years after their operation.
The procedure entails stapling the stomach and re-routing the intestines, so that food that is consumed bypasses most of the stomach and caloric consumption is reduced.
These issues are unlikely to be confined to this type of weight-loss surgery alone, said study author Dr. Thomas Boerlage. He is a researcher in the department of internal medicine at MC Slotervaart, in Amsterdam, the Netherlands.
"I would very much expect other bariatric [weight-loss] procedures to [cause] gastrointestinal complaints, too," Boerlage cautioned. He said that gastric banding, along with newer types of weight-loss options, are "fairly certain" to spark long-term gastrointestinal complications.
Boerlage pointed out that "it was already known from previous studies that patients can develop gastrointestinal complaints after a Roux-en-Y gastric bypass. However, most of those studies concerned only the first year after surgery, and you can imagine that people might have complaints shortly after surgery, whatever kind of surgery it is."
To assess the risk for long-term gastrointestinal complications, Boerlage's team focused on the experience of nearly 250 patients who underwent the surgery in 2012. All completed a gastrointestinal and food tolerance survey two years after undergoing the procedure. The patients' answers were stacked up against those of 295 comparably obese patients who had not undergone surgery.
By most measures, the weight-loss surgery patients were found to be struggling with significantly more gastrointestinal disturbances at the two-year mark than those who hadn't undergone the procedure, the investigators found.
For example, surgery patients were found to be saddled with more abdominal pain, diarrhea, indigestion and constipation, compared with the non-surgical group. Surgery patients did, however, report lower levels of both hunger pain and acid regurgitation, compared with non-surgical patients.
In terms of food intolerance, 176 surgery patients (70 percent) said they experienced some form of intolerance to an average of four different foods, and more than 90 percent said the problem arose only after surgery.
Problematic foods tended to include red meat and items characterized by high amounts of fat or sugar, such as sodas, cakes, pies, pastries and fried foods, according to the report.
That said, only about 14 percent of those experiencing ongoing long-term food intolerance said the issue bothered them "very much" or "much."
Still, less than 17 percent of the non-surgical group reported experiencing any comparable type of eating problem.
Boerlage and his colleagues reported their findings in the Dec. 19 issue of the British Journal of Surgery.
So what are bypass patients to do?
"In general, it is advisable for patients to stick tightly to the dietary guidelines that are given after surgery," said Boerlage. "This will surely help to alleviate symptoms, although not all symptoms can be prevented," he added.
"We do advise our patients to avoid certain foods with a high sugar or fat content. And, indeed, these are the types of food that are a problem in obese patients in the first place. So, in a way you could say that these complaints are also useful because they remind patients to avoid certain foods," Boerlage suggested.
Dr. John Morton, chief of bariatric and minimally invasive surgery at the Stanford School of Medicine in California, agreed. He suggested that the problem can be easily fixed if patients strictly follow standard nutritional advice.
"These concerns are due solely to dietary indiscretions by patients," Morton said. "If you follow dietary recommendations you will avoid these issues."
What's more, Morton stressed that, for many, weight-loss surgery is a "lifesaving procedure," one whose benefits "clearly outweigh" any dietary downside.
Explore further: Weight loss surgery linked to gastrointestinal complaints
Visit the U.S. National Institute of Diabetes and Digestive and Kidney Diseases for more on weight-loss surgery.