MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Ischemic Colitis


Parswa Ansari

, MD, Hofstra Northwell-Lenox Hill Hospital, New York

Reviewed/Revised Apr 2023
Topic Resources

Ischemic colitis is injury of the large intestine that results from an interruption of blood flow.

  • Abdominal pain and bloody stools are common.

  • Computed tomography is usually done, and colonoscopy is sometimes done.

  • Most people get better with fluids given by vein and by not eating or drinking anything, but a few require surgery.

Ischemic colitis results from an interruption of blood flow through arteries that supply the large intestine. Often doctors cannot find a cause for the reduced blood flow, but it is more common among people with heart and blood vessel disease, people who have had surgery on their aorta, or people who have problems with increased blood clotting. Ischemic colitis primarily affects people who are 60 or older.

Reduction of blood flow damages the inside lining and inner layers of the wall of the large intestine, causing ulcers (sores) in the lining of the large intestine, which can bleed.

Symptoms of Ischemic Colitis

Usually, the person has abdominal pain. The pain is felt more often on the left side, but it can occur anywhere in the abdomen.

The person frequently passes loose stools that are often accompanied by dark red clots. Sometimes bright red blood is passed without stool.

Low fevers (usually below 100° F [37.7° C]) are common.

Diagnosis of Ischemic Colitis

  • Computed tomography (CT) or sometimes colonoscopy

A doctor may suspect ischemic colitis on the basis of the symptoms of pain and bleeding, especially in a person older than 60. It is important for doctors to distinguish ischemic colitis from acute mesenteric ischemia Acute Mesenteric Ischemia Acute mesenteric ischemia is sudden blockage of blood flow to part of the intestines, which may lead to gangrene and perforation (puncture). Severe abdominal pain develops suddenly. The diagnosis... read more , a more dangerous condition in which blood flow to part of the intestine can become completely and irreversibly blocked.

Treatment of Ischemic Colitis

  • Fluids by vein

  • Antibiotics

  • Rarely surgical repair

People with ischemic colitis are hospitalized.

Initially, the person is given neither fluids nor food by mouth so that the intestine can rest. Fluids, electrolytes Overview of Electrolytes More than half of a person's body weight is water. Doctors think about water in the body as being restricted to various spaces, called fluid compartments. The three main compartments are Fluid... read more , antibiotics, and nutrients are given by vein (intravenously). Within a few days, eating and drinking are resumed.

If people develop scar tissue, surgical repair may be needed.

Prognosis for Ischemic Colitis

Nearly all people with ischemic colitis improve and recover over a period of 1 to 2 weeks. However, when the interruption to the blood supply is more severe or more prolonged, the affected portion of the large intestine may have to be surgically removed.

Rarely, people get better but later on develop scar tissue in the affected area.

quiz link

Test your knowledge

Take a Quiz!