What effects if any does caffine have on ulcers?

It is believed that coffee may affect stomach acidity as well as motility, worsening symptoms related to peptic ulcer disease. Research remains equivocal, caffeine is not believed to cause ulcers otherwise.

May depend on the source for caffeine. Caffeine increases Stomach emptying, so this may increase small bowel irritation, ulcers, but improve those in the stomach. Coffee is associated with increased ulceration with or without caffeine. If this does not answer your question, please re submit a new question.