I was on Wellbutrin for twelve years, went off it for a year and now am back on. I've always had digestive issues (even had my colon removed) so I can't say for sure. I did look up side effects on drugs.com and the only digestive issue seems to be constipation. I hope someone else can chime in with their experiences...

http://www.drugs.com/sfx/wellbutrin-side-effects.html