Ischemic colitis occurs when there is not enough blood flowing to the colon, also known as the large intestine. It is more likely to occur in people who are over 60, smoke cigarettes, or have diabetes.

Ischemic colitis is the most common type of gut-based ischemia, accounting for 1 in every 2,000 hospital admissions. Ischemia refers to a condition where there is restricted blood flow.

Symptoms of ischemic colitis include pain, tenderness, and digestive problems. It is often mistaken for inflammatory bowel disease (IBD) or other gastrointestinal issues.

The condition can develop over time (chronic) or come on suddenly (acute). Sometimes, chronic ischemic colitis can heal on its own, but some people may still need treatment to prevent infection or colon damage.

Doctors consider acute ischemic colitis to be a medical emergency that requires urgent care.

This article describes the causes and symptoms of ischemic colitis, along with the available treatment options. It also explores the diagnosis and prevention of the condition.

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The most typical symptom of ischemic colitis is stomach cramping and pain. The pain may be mild or moderate, and it often occurs suddenly. Typically, pain occurs on the left side of the abdomen.

Some people may notice blood in their stool, but excessive bleeding suggests another condition, such as:

A person should speak to a doctor if they find blood in their stool.

Other symptoms of ischemic colitis include:

The risk of complications is higher when symptoms develop on the right side of the stomach, and pain in this area may be more severe as well. Pain on the right side suggests a blockage in the arteries leading to the small intestine as well as the colon.

Ischemic colitis often occurs on the left side of the colon.Share on Pinterest
Medical illustration by Yaja’ Mulcare

A lack of blood flow to the colon causes ischemic colitis. This lack of blood flow (ischemia) can occur for many reasons.

In people with coronary artery disease or peripheral vascular disease, inadequate blood supply may result from a hardening of the mesenteric arteries that lead to the intestines.

Other factors that contribute to ischemic colitis include:

Rarely, medications can cause ischemic colitis, including:

Certain factors increase a person’s chance of developing ischemic colitis. These include:

  • Age: Adults over the age of 60 are most at risk, possibly because arteries tend to harden with age.
  • Clotting abnormalities: Disorders such as Factor V Leiden increase the risk of blood clots.
  • Other medical conditions: Atherosclerosis, diabetes, congestive heart failure, IBS, and low blood pressure all increase the risk of ischemic colitis. It is unclear whether IBS increases the risk of ischemic colitis because of changes in bowel habits, the medications for the condition, or a combination of the two.
  • Prior surgery: People who have previously had surgery involving the aorta or abdomen are at higher risk than others of developing ischemic colitis.
  • Lifestyle: Engaging in strenuous activities, such as running a marathon, can limit blood flow to the colon. Smoking can also increase the risk of developing the condition. Some illegal drugs, such as cocaine and methamphetamines, can also cause ischemic colitis.
  • Medications: In rare cases, medications can cause ischemic colitis, particularly those that regulate blood pressure or alleviate constipation.

Treatment for ischemic colitis depends on its severity.

Mild cases may resolve within a few days. If a person requires treatments, they include:

  • antibiotics to prevent infection
  • a liquid diet
  • intravenous (IV) fluids to prevent dehydration
  • medication for pain relief

Other ways to manage the condition include treating underlying medical conditions, including diabetes and congestive heart failure, and avoiding medications that cause vasoconstriction (narrowing of the blood vessels).

Acute ischemic colitis is a medical emergency. Treatments include medications such as thrombolytic drugs for blood clots or vasodilators to widen narrow arteries.

Typically, a healthcare professional will perform a follow-up colonoscopy to check for healing and complications.

Severe ischemic colitis that does not respond to other treatments may require surgery. An estimated 20% of people with the condition will need some form of surgical intervention.

Those with underlying medical conditions are more likely to need surgery.

Surgeons may:

  • repair damage to the colon and remove scar tissue using laparotomy
  • bypass a blockage in the mesenteric arteries, usually through laparoscopy
  • open the narrowing in a blood vessel and insert a stent using angioplasty

Ischemic colitis shares symptoms with other digestive disorders, particularly inflammatory bowel diseases, which include Crohn’s disease and ulcerative colitis. This can make diagnosis more complicated.

After taking a medical history, a doctor may order imaging tests to confirm a diagnosis and rule out other conditions. Imaging tests that doctors use to diagnose ischemic colitis include:

  • Ultrasound or abdominal CT scan: Both ultrasound and CT scans allow doctors to see images of the colon and intestines.
  • Mesenteric angiogram: This test uses X-rays to detect blockages inside the arteries that supply the intestines with blood.

Other diagnostic tests include:

  • Blood test: If a blood test shows a high white blood cell count, it suggests acute ischemic colitis.
  • Stool analysis: A stool sample can help identify if an infection is causing the symptoms.
  • Colonoscopy: This involves inserting a flexible tube into the rectum to the colon. The tube has a light and a camera that allow the doctor to see images of the colon.

After diagnosing somebody with ischemic colitis, a doctor will inform that person about their condition.

A 2021 review stresses the importance of doctors educating people with a recent ischemic colitis diagnosis about the signs of disease progression. This can greatly improve healthcare outcomes in the future.

If a person has ischemic colitis, they may see a variety of healthcare professionals. For example, nurses may need to take blood samples for testing, and imaging technicians can help to gauge disease severity.

Some questions a person may wish to ask their doctor after receiving an ischemic colitis diagnosis include:

  • Which treatment options are available and what do they involve?
  • Are there any side effects associated with medication for ischemic colitis?
  • Can any lifestyle changes help to prevent symptoms?
  • What is the probable cause?
  • How long is the recovery time?
  • How does ischemic colitis progress?

The most serious complication of ischemic colitis is gangrene (tissue death). Gangrene results from a loss of blood flow to the tissue and can be life threatening. People who experience gangrene need surgery to remove the blockage and damaged tissue.

Other complications include:

Is ischemic colitis fatal?

Ischemic colitis can be fatal. One study suggests that the overall mortality rate is around 22%.

However, this depends on the ischemic colitis subtype and many other factors. For example, nongangrenous ischemic colitis has a mortality rate of less than 5%.

It may be possible for people to reduce their chances of developing chronic ischemic colitis. For example, because smoking is a risk factor for this condition, avoiding tobacco smoke can make ischemic colitis less likely.

This may involve stopping smoking or avoiding secondhand smoke.

There is also evidence that certain conditions, such as atherosclerosis, can make ischemic colitis more likely to occur. Preventing those conditions can also help avoid ischemic colitis.

For example, research suggests that people can lower their risk of developing atherosclerosis by doing the following:

  • regularly exercising
  • maintaining a healthful, balanced diet
  • maintaining a healthful bodyweight

Most people with chronic ischemic colitis recover with medication, and those experiencing severe ischemic colitis can have surgery. People may need to make some lifestyle changes to prevent the condition from returning.

Examples of helpful lifestyle changes include quitting smoking, exercising regularly, and eating a balanced diet. People may need to stop taking medications that contribute to ischemic colitis, with a doctor’s advice.

Acute ischemic colitis has a poorer outlook and a higher mortality rate than chronic ischemic colitis because it can cause gangrene. Swift medical treatment is crucial in acute cases.

People who experience symptoms of ischemic colitis should see a doctor promptly to improve their outlook and reduce the risk of complications. People should not ignore bloody stools. A person should seek emergency medical attention for severe abdominal pain that makes it difficult to sit down or get comfortable.