Stomach cancer, also called gastric cancer, is characterized by a tumor that develops in the stomach’s upper-middle part. Almost 95% of stomach cancers develop in the cells present in the stomach’s outer lining, but rarely, the cancer may also begin in the organ’s connective tissues or lymph nodes. The progression of this disease is slow, but it may eventually spread to the pancreas and liver if left untreated. Here are early warning signs of stomach cancer: Diarrhea or constipation If the cancerous cells multiply and spread to the small intestine, it can cause blockages, resulting in diarrhea. On the other hand, abdominal tumors can cause the bowel to narrow, further causing constipation. Stomach inflammation If gastric cancer spreads to the tissue lining the abdomen, the stomach may swell up as a result of the accumulation of a fluid called ascites. Nausea and vomiting Since the stomach is an indispensable part of the gastrointestinal tract, cancerous tumors in the stomach may cause blockages when they begin spreading to other organs. This might lead to nausea and vomiting. Abdominal pain Many patients with gastric cancer may suffer from excruciating abdominal pain. Also, the cancer may spread to the back if it originates in the stomach’s lymph nodes.