What important digestive functions do people lose when the lower stomach is bypassed?
In normal anatomy (i.e. no surgery) and in gastric bypass patients, absorption of nutrients takes place in the small intestine. In the Gastric Bypass the mixing of digestive juices (i.e. bile and pancreatic juice) with nutrients and the absorption of those nutrients still happens. The capacity and acid production of the lower stomach are to help a person digest large bulky meals—this ability was necessary in evolutionary times when meals were not regularly available but it represents excess capacity in today’s society. The bypassed stomach and small intestine do play important roles in the absorption of Iron, Calcium, and Vitamin B12—thus we require the patients to take supplements and we follow blood levels of these and other nutrients.
