What can cause severe stomach pain?

Perforating lesion: While abdominal pain associated with an ulcer can be severe it best responds to antacids or meds reducing acid production. The true almost intolerable pain however is associated with the distal stomach ulcer that freely perforates into the retroperitoneum or lesser sac. Here the pain persists until surgical intervention to control the leakage of gastric fluid.

A lot of things: Gastritis, an ulcer, gall bladder disease, and indigestion can all cause stomach pain after eating. Gas, irritable bowel syndrome, and constipation can cause stomach pain. Severe pain may indicate a blockage in the bowels or appendicitis, among other things.

More info: There are many causes of abdo pain. How soon after eating? What type? How long does it last? Anything make it better? Anything make it worse? Do certain foods affect the pain? Have you had any surgery ? How long has it been there? Have you tried any medications? Did they work? Did you injure yourself? Pulled muscle etc? Has anyone done any studies? See a md for exam and studies. If severe --> er.