Gastric bypass is reversible.
More Info: Although a gastric bypass can indeed be undone, there are a number of reasons why this turnabout procedure is not a good idea.
Because no organs are removed during the process, the stapling of the stomach or other gastric methods can in theory be undone. But the existing scar tissue makes the repeat operation more difficult; there is an increased risk of bleeding; and getting the suture or staple lines to heal after a second operation is often more difficult.
Damaged Nerve Endings
An even bigger issue is the challenges involved in reconnecting the truncated portions of the stomach and intestines as they had been before, a virtually impossible task. Several of the nerve endings severed during the original gastric bypass are irrevocably damaged. By undoing the associated changes, a patient may be subject to an ailment known as post-op gastroesophageal reflux disease.
It also depends what kind of gastric bypass was performed. For example, a laparoscopic banding procedure, which involves an inflatable device full of saline that is sewn around the stomach, is a lot easier to reverse. But again, the re-healing of sutures if a potential, likely problem, and as with all gastric reversals, patients are likely to gain back part if not all of the weight they had lost thanks to the procedure.
More than 100,000 gastric bypasses are now carried out each year in U.S. hospitals. In a country where more than half the population is overweight and up to 10% "morbidly obese," this is no real surprise. The aforementioned lap-band bypasses are particularly popular, gaining year-to-year faster than traditional surgeries.
Another reason for the popularity of lap-band gastric bypasses is that they are the easiest to reverse, even though doctors ultimately caution against this undoing. U.S. health insurance companies are also covering more and more of the operations, further fueling the move by patients towards the procedure, and a form, which can be later changed back, if necessary.