The jejunum, with its long villi, large absorptive surface, highly concentrated digestive enzymes, and many transport carrier proteins, is the primary digestive and absorptive site for most nutrients. Thus, when the jejunum is resected, there is a temporary reduction in absorption of most nutrients. This reduction in absorption is compensed by adjustments in the ileum.
The ileum is capable of undergoing rather massive adaptation with significant growth in length and function of ileal villi. As a result, there is a gradual improvement in macronutrient absorption following jejunal resection as the ileum adapts.
In regards specficially to alcohol, it is unclear how jejunal bypass affects this. It is primarily metabolized by the liver - and obtaining liver function tests can help assess this. If you decided to have the procedure reversed, it may help with carbohydrate absorption, but the effects on alcohol absorption would be unclear.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.