What Is Ischemic Colitis?
Ischemic colitis is inflammation of the colon ( a part of the large intestine) due to impaired blood flow (colonic ischemia), usually appearing in persons after 50 years of age. This may trigger sudden (acute) or long term (chronic) abdominal pain, blood in the stool and diarrhea. Injury of the colon may be mild and temporary or severe and requiring surgery.
Symptoms of chronic ischemic colitis may slowly develop over a long period of time, or appear as a flare and may include:
- Lower left side abdominal pain, or pain anywhere else in the stomach
- Bright red blood in the stool
- Diarrhea, or urgency to have a bowel movement
- Low grade fever
Causes of Chronic Ischemic Colitis
Chronic ischemic colitis (1) mostly affects persons after 60 with diabetes or heart disease due to atherosclerosis of the small arteries that supply the colon. When chronic ischemic colitis appears in a person below 50 years of age, it is likely due to impaired blood clotting (thrombosis).
Diagnosis of chronic ischemic colitis can be usually confirmed by colonoscopy, during which inflammation with occasional bleeding ulcers can be seen. In doubtful cases, a small sample (few millimeters) of colonic tissue can be cut (biopsy) and checked under the microscope; finding blood cells in the tissue below mucosa support diagnosis of ischemic colitis. An X-ray with contrast substance injected into circulation (abdominal arteriogram), or MRI may show blocked arteries, but this is usually not necessary (1). Blood test usually shows elevated white cells and Hemoccult test usually reveals blood in the stool.
Treatment and Diet
In mild cases, drugs to maintain appropriate blood pressure, and antibiotics to prevent infection of the colon may be given. With such a conservative treatment symptoms should be relieved in few days.
A person with severe symptoms should be admitted to hospital. Feeding by mouth is stopped and all fluid, and nutrients are given by intravenous infusion. Follow-up colonoscopies may be done to monitor progression or cessation of changes in the colonic mucosa. Treatment may last from several days to few weeks, depending on severity of inflammation.
Any underlying disease should be treated, and appropriate blood pressure and cholesterol level should be maintained to stop progression of atherosclerosis. Patient should quit smoking and be active to stimulate circulation. Healing depends on the extent of arterial damage and patient’s overall health condition.
Complications and Surgery
A common complication of chronic ischemic colitis is growth of the fibrous tissue (strictures) in the colonic wall and may obstruct the passage of the bowel content. Such a tissue has to be surgically removed.
If a major abdominal artery is completely obstructed, death of the affected part of the colon (gangrene), colon puncture (perforation), or inflammation of membrane that covers abdominal organs (peritonitis) may occur. These complications requires urgent surgery – the removal of the affected part of the colon; prognosis is bad.
In severe cases, infection may spread from the colon to the blood (sepsis). Aggressive antibiotic treatment and often a blood transfusion are needed to treat this life threatening condition.
- Chronic ischemic colitis (merck.com)