4 days having bad pain in stomach after i eat.have had bowel movements.gallbladder been removed yrs ago, have ibs.what else could this be?

Gallbladder: When the gall bladder is removed, there is no "Bag" to store the bile... thus this continually leaks into the bowel. Fatty food may cause more bile to be produced ... Bile is very irritating to the bowel thus it may cause you to have loose stools or increased gas production. however you may also have a mild form of food poisoning. Consult your MD is it persist over the next day or so.

Ulcer possible: It could be an ulcer or just a bad case of gastritis. I would like you to get a good history and physical exam from your doc who can steer you the right way, possibly to a GI doc. Hope this helps. Be well!