Ischemic colitis (IC) is inflammation of the large intestine (colon). It occurs when for one reason or another, not enough blood flows to the colon. IC is most common among those over the age of 60, though it can occur at any age (Baixauli, et al., 2003).
Chronic (long-term) IC is caused by hardening of the arteries (atherosclerosis). In cases of chronic IC, the condition often resolves itself. It may also go away with mild treatment, such as a short-term liquid diet and antibiotics.
Acute (sudden) IC is usually caused by a blood clot. Acute IC is a medical emergency and must be treated quickly. The mortality rate is high if gangrene (tissue death) occurs in the colon.
IC is also called mesenteric artery ischemia, mesenteric vascular disease, or colonic ischemia.
IC occurs when there is not enough blood flow to the colon. A reduction in blood flow (which is also called “infarction”) may be caused by hardening of one or more of the mesenteric arteries. These are the arteries that serve the intestines). This hardening is a common cause of IC among patients who have a history of coronary artery disease or peripheral vascular disease, in which other arteries in the body harden.
A blood clot can block the mesenteric arteries and stop or reduce blood flow. Clots are more common in patients with irregular heartbeat (arrhythmia).
According to the Cleveland Clinic Journal of Medicine, about 90 percent of cases of IC occur in patients over 60 years old (Baixauli, et al., 2003). This may be due to age-related hardening of the arteries.
You have increased risk of developing IC if you
- have congestive heart failure
- have diabetes
- have low blood pressure
- have damage to the aortic artery (the main artery that supplies blood to the heart)
- take medications that have constipation as a side effect
According to the Cleveland Clinic Journal of Medicine, 60 percent of patients with IC feel mild to moderate abdominal pain (Baixauli, et al., 2003). This pain often occurs suddenly and feels like stomach cramps. Some blood may be present in the stool, although bleeding is not severe. Lots of blood in the stool may indicate a different problem such as Crohn’s disease, colorectal cancer, or hemorrhoids.
Other symptoms include:
- pain in the abdomen after eating
- an urgent need to defecate
- tenderness in the belly
IC can be hard to diagnose. According to the Cleveland Clinic Journal of Medicine, IC is easily mistaken for inflammatory bowel disease, a group of diseases that includes Crohn’s disease and ulcerative colitis (Baixauli, et al., 2003).
If your doctor suspects you might have IC, he or she will ask about your medical history and will order diagnostic tests, including:
- a Doppler ultrasound or CT scan to create images of the blood vessels and intestines
- a mesenteric angiogram, in which X-ray images are taken of the arteries to reveal where the blockage has occurred
- blood tests, to count the number of white blood cells and check your blood acid level (a high white blood cell count may signify acute IC)
Mild cases of IC are often treated with:
- a liquid diet
- intravenous fluids (IV fluids)
- pain medication
Acute IC is an emergency. It may require:
- thrombolytics (medicines that dissolve blot clots)
- vasodilators (medicines that widen the mesenteric arteries)
- surgery to remove the arterial blockage
For patients with chronic IC, surgery to remove the arterial blockage is generally only required if other treatments fail.
According to the Cleveland Clinic Journal of Medicine, about 20 percent of patients with acute IC need surgery. Patients who are ill enough to require surgery have a mortality rate between 30 and 60 percent (Baixauli, et al., 2003).
According to the National Institutes of Health, the most dangerous complication of IC is tissue death (NIH, 2012). When blood flow to the colon is restricted, tissue may become gangrenous (wither and die). If this occurs, surgery may be required to remove the dead tissue.
Other complications associated with IC include
- perforation (a hole) in the intestine
- peritonitis (inflammation of the tissues of the abdomen)
- sepsis (a very serious, wide-spread bacterial infection)
Most people with chronic IC can be successfully cured with medication and surgery. However, the problem may come back if healthy lifestyle changes are not made as the arteries will continue to harden.
The outlook for patients with acute IC is often poor because tissue death in the intestine frequently occurs before surgery. The outlook is much better if the condition is diagnosed and treated right away.
A healthy lifestyle can reduce your risk of developing hardened arteries. Basics of a healthy lifestyle include:
- getting regular exercise
- eating a healthy diet
- treating heart conditions, such as irregular heartbeat, that can lead to blood clots
- keeping blood cholesterol and blood pressure under control
- not smoking