Stomach cancer can be hard to find early. Often there are no symptoms in the early stages and, in many cases, the cancer has spread before it is found. When symptoms do occur, they are often so vague that the person ignores them. Stomach cancer can cause the following: Indigestion or a burning sensation (heartburn); Discomfort or pain in the abdomen; Nausea and vomiting; Diarrhea or constipation; Bloating of the stomach after meals; Loss of appetite; Weakness and fatigue; and Bleeding (vomiting blood or having blood in the stool).

Any of these symptoms may be caused by cancer or by other, less serious health problems, such as a stomach virus or an ulcer. Only a doctor can tell the cause. People who have any of these symptoms should see their doctor. They may be referred to a gastroenterologist, a doctor who specializes in diagnosing and treating digestive problems. These doctors are sometimes called gastrointestinal (or GI) specialists. Diagnosis To find the cause of symptoms, the doctor asks about the patient's medical history, does a physical exam, and may order laboratory studies.