Signs and Symptoms of Gastrointestinal Stromal Tumors

Most gastrointestinal stromal tumors (GISTs) occur in the stomach or small intestine. These tumors might not cause any symptoms unless they are in a certain location or grow to a certain size. Small tumors might not cause any symptoms and may be found accidentally when the doctor is looking for some other problem. These tumors are often benign.

Blood loss

GISTs are often found because they cause bleeding into the gastrointestinal (GI) tract. Signs and symptoms of this bleeding depend on how fast it occurs. Brisk bleeding into the stomach or small intestines can make bowel movements black and tarry. Brisk bleeding into the stomach can also cause a person to vomit blood. When the blood is thrown up it may be partially digested and so look like coffee grounds. Bleeding from the esophagus can also cause the person to throw up blood. Brisk bleeding into the large intestines is likely to turn the stool red with visible blood.

If the bleeding is slow, it often doesn’t cause the person to throw up blood or have a change in their stool. Over time, though, slow bleeding can lead to low red blood cell counts (anemia), and make a person feel tired and weak.

Bleeding from the GI tract can be very serious. If you have any of these signs and symptoms you should see your doctor right away.

Other possible symptoms of GISTs

  • Abdominal (belly) discomfort or pain
  • A mass or swelling in the abdomen
  • Nausea, vomiting
  • Feeling full after eating only a small amount of food
  • Loss of appetite
  • Weight loss
  • Problems swallowing (for tumors in the esophagus)

Sometimes the tumor grows large enough to block the passage of food through the stomach or intestine. This is called an obstruction, and it causes severe abdominal pain and vomiting. It can even cause a hole (perforation) to develop. Emergency surgery is often needed to treat the blockage.

Although many of the symptoms of GIST (like belly pain and nausea) can be caused by things other than cancer, if you have these symptoms, especially if they last for more than a few days, you should see your doctor.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: April 4, 2014 Last Revised: February 8, 2016

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.