Definition and Overview
Ischemic colitis occurs when blood flow to the large intestine (colon) is reduced due to a blocked or narrowed blood vessel. When the colon does not receive enough oxygen, its lining (mucosa) undergoes necrosis (tissue or cell death). This causes ulcers to form.
There is no strong statistical data to support the prevalence of the condition. This is mainly because it is transient and usually disappears after a few days. It is also commonly misdiagnosed because it shares similar symptoms with other gastrointestinal (GI) diseases. These include ulcerative colitis, diverticulitis, and even colon cancer.
Ischemic colitis can be either mild or severe. Its treatment depends on its severity, underlying disease, and how soon the patient is diagnosed. The majority of patients are able to recover fully after a few weeks with no complications. However, about 10 percent develop scarring on the colon tissue. Such cases require surgery.
Causes of Condition
Ischemic colitis occurs when arteries that supply blood to the large intestine are narrowed or blocked. Factors that can increase the risk of the disorder are:
Age - It is more common among senior adults between the ages of 60 and above.
Complications of aortic surgery - The aorta is the main and biggest artery in the body. Arteries that supply blood to the colon are connected to it. When the aorta is damaged by surgery, the amount of blood that flows toward the colon is reduced. This prevents the colon from getting the amount of oxygen and nutrients it needs.
Plaque build up on the arterial wall - When left unchecked or untreated, this can progress and cause the walls to narrow. This is one of the common reasons why blood flow to different organs is reduced.
Low blood pressure - When the blood supply from the heart passes through the arteries, it pushes against the arterial walls. The measurement of such push is called blood pressure. The normal blood pressure is 120/80. These numbers can go up and down throughout the day. Low blood pressure is when these numbers are consistently low. Common causes include certain medications and underlying diseases, such as heart failure. The weak force means that not enough blood supply is reaching the vital organs.
Blood clot - Blood clotting is the body’s mechanism to prevent excessive blood loss when a person is wounded. However, blood clots sometimes get stuck in the arteries and prevent blood from flowing.
Obstruction - Besides blood clots, abnormal growths can also obstruct the GI tract or the arteries. This can shut off or reduce blood supply to the colon.
The main symptoms of the disorder are severe cramps and abdominal pain. The pain can begin anywhere in the abdomen but commonly affects the left side first. If it travels to the right side, it could mean that the small intestine is also affected. Other symptoms are diarrhea and passing bloody stool. The patient may also feel the need to pass stool more frequently.
Who to See and Types of Treatments Available
Symptoms of ischemic colitis should be brought to the attention of a gastroenterologist. Tests used to diagnose the disorder are blood and stool exams. Imaging tests such as computed tomography (CT) scan, x-ray of the colon, and a colonoscopy may also be performed. These tests help doctors confirm or rule out other GI diseases.
Treatment is not always necessary. If the patient doesn’t show any serious symptom or there’s no blockage, hospitalisation or medications are not needed. Often, the condition goes away on its own within a few days.
However, inpatient administration is necessary in severe cases. Usually, the patient is not allowed to eat for a couple of days. Instead, they are provided the nutrients they need through an IV. The doctor may also prescribe antibiotics to prevent infections.
Surgery is used when there is damage to the colon or if it is blocked. The surgeon will remove the damaged or necrotic parts to speed up the healing process and avoid serious complications. Blocked arteries are also unclogged or widened through angioplasty. This restores normal blood flow to the colon.
Meresse, B; Ripoche, J; Heyman, M; Cerf-Bensussan, N (October 2008). “Celiac disease: from oral tolerance to intestinal inflammation, autoimmunity and lymphomagenesis”. Mucosal Immunology. 2: 8–23. PMID 19079330. doi:10.1038/mi.2008.75.
Kaiser MM, Wenk H, Sassen R, Müller G, Bruch HP (April 1996). “[Ischemic colitis after vascular surgery reconstruction of an abdominal aortic aneurysm]”. Der Chirurg 67 (4): 380–6. PMID 8646925.