Common symptoms of a bleeding stomach ulcer, or gastric ulcer, include a burning or gnawing pain in the middle or upper stomach at night or between meals, heartburn, bloating and nausea, or vomiting, according to WebMD. Small gastric ulcers may also be asymptomatic, or without symptoms.
In more severe gastric ulcers, symptoms can include vomiting blood that looks like coffee grounds, weight loss, dark or black stool, and severe pain in the middle to upper abdomen. According to MedlinePlus, most ulcers occur in the first layer of the stomach's inner lining. A hole that goes through the stomach, or a perforation, is much more serious and demands immediate medical attention.