Stomach ulcer. Coloured barium X-ray of a gastric ulcer (red) in a patient's stomach (pink). The ulcer is in the antrum, the last region of the stomach before the small intestine (blue) begins. Gastric ulcers develop when digestive secretions in the stomach attack its lining. They may be promoted by aspirin or bacteria. Symptoms include abdominal pain and vomiting blood, which can be relieved by antacid drugs. Most ulcers heal if anti-secretory drugs are taken, but surgery to cut the vagal nerve (responsible for stomach acid production), or to remove part of the stomach, may be required.