Bowel Function After Duodenal Switch
The main questions pre-op patients usually have about Duodenal Switch (D.S.) revolve around bowel function. These are the questions our expert surgeons will address:
Do DS patients have chronic diarrhea? NO
Do DS patients spend all day on the toilet? NO
Do DS patients have control over their bowels? YES
Do DS patients have to wear diapers for the rest of their lives!? NO
These are probably the most outrageous pieces of misinformation that is being promoted by those who do not offer D.S. as an alternative to their patients, and patients who wish to justify their reasons for choosing alternative procedures. There will always be patients on either end of the spectrum; some will have a lot more bowel movements than the average post-op patient and some will have far fewer or be constipated. These extreme issues are very rare and are dealt with by the surgeon or other medical specialists. Almost all cases lose frequent bowel function that can be traced back to a patients’ dietary intake. One of the most common contributing factors is excessive fat intake. There is the misconception that since D.S. limits fat absorption, then excessive amounts of fat can be tolerated and some also suggest that it is needed. Both of these may be incorrect; not only does this contribute to excessive loose bowel movements, but it also contributes to the associated loss of nutrients and minerals, such as potassium, vitamin D and serious hydration issues.
This is just not the case for the majority of patients. Most D.S. post-op patients have 2-3 bowel movements per day.
What the experts say…
Baltasar et al., “Gastric emptying in patients with morbid obesity treated with a duodenal switch”, May 1997. 
81.3% of Duodenal Switch patients experience normal gastric emptying.
Gary Anthone, MD, “The duodenal switch operation for morbid obesity”, Aug 2005. 
The average number of bowel movements per day for 43 pre-op patients was 1.9, 421 patients six months post-op was 2.7, 316 patients twelve months post-op was 2.6 and 113 patients > thirty six months post-op was 2.8.
Wasserberg et al., “Bowel habits after gastric bypass versus the duodenal switch operation.”, Dec 2008. 
Although duodenal switch is associated with more bowel episodes than other weight loss procedures, the difference is not statistically significant. Bowel habits are similar in patients who achieve 50% estimated body weight loss with duodenal switch surgery or gastric bypass.
Marceau et al., “Duodenal Switch: Long-Term Results”, Nov 2007, p 1428. 
There are negative side effects with DS that is worth mentioning. The unpleasant odor of stool and is always exacerbated by patients’ dietary choices. Artificial sweeteners, carbonated drinks, carbohydrate intake (simple and complex) can all cause or worsen the flatulence after the DS.