Early symptoms of abdominal tumors include indigestion, heartburn and loss of appetite, according to WebMD. Additional early symptoms include slight nausea and bloating after eating a meal. As tumors grow, additional symptoms include stomach swelling, unexplained weight loss, yellowish skin or eyes, vomiting and bloody stools.
Weakness or fatigue, difficulty swallowing, stomach pain, constipation and diarrhea are additional symptoms of abdominal tumors, explains WebMD. Abdominal tumors can grow large enough to prevent food from passing through the intestine or stomach, reports the American Cancer Society. Such obstructions can cause a perforation, and sometimes emergency surgery is required to remove the blockage.
The diagnosis of abdominal tumors begins with a physical examination, notes WebMD. Blood tests and biopsies are taken to detect whether the abdominal tumors are cancerous. The physician may perform an upper endoscopy, where a thin, flexible tube is inserted down the patient's throat. An attached camera then allows the doctor to view the tumors and collect a small piece of stomach tissue for the biopsy.
The doctor may also perform an upper gastrointestinal series test, states WebMD. The patient drinks barium, a chalky liquid substance, that allows the doctor to see tumors more clearly on an X-ray. A computed tomography, or CT, scan can create detailed images of suspected abdominal tumors.