Hello Zehntuhl,
Prilosec is blocker of hydrogen pump and it will lower acidity in your gut, consequence of it will be stoping og further damage caused by stomach acid. Your intestines will have to heal by itselves as Prilosec will just stop acid to make more damage. My opinion is that it may be useful to stopa damage but repair will be upon other things which John was talking about. If blood in your stool is red than it comes from lomer parts of your intestines and if it is dark, almost black it is gastric ulcer.
