Introduction:
Colon ischemia is a disorder that develops when a partial or complete blockage reduces the blood supply to the colon. The blockage usually occurs in one or more arteries that supply the large intestine. The reduced blood flow can cause insufficient delivery of oxygen and nutrients required for cellular metabolism, resulting in tissue damage. Colon ischemia is also known as ischemic colitis.
What Are the Causes of Colon Ischemia?
Colon ischemia can be acute (start suddenly) or chronic (develop over time). Colon ischemia occurs when there is a decrease in blood flow in the arteries of the large intestine. The possible causes of colon ischemia include:
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Atherosclerosis: Cholesterol builds up in the arteries supplying the large intestine
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Blood Clots: Blood clots can partially or completely block the supply of blood to the intestine. Clots are more common in people with irregular heartbeat or arrhythmia.
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Blood Pressure: Low blood pressure due to trauma, dehydration, shock, or heart failure can also reduce the blood flow to the colon.
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Bowel Obstruction: Bowel obstruction caused by a tumor, hernia, or scar tissue can reduce blood flow.
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Medical Conditions: Conditions that affect the blood, such as vasculitis (inflammation of the blood vessels), sickle cell anemia, or lupus, can also cause colon ischemia.
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Medications: The use of certain medications can cause colon ischemia. These include some heart and migraine medications, opioids, hormone medications like estrogen, chemotherapy medications, and medications for irritable bowel syndrome.
What Is the Risk Factor for Colon Ischemia?
The factors which increase the risk of colon ischemia include:
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Age: The condition occurs more frequently over the age of 60.
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Sex: Ischemic colitis is more common in women.
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Abnormal Blood Pressure: Blood pressure that is too high or too low can cause ischemic colitis.
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Smoking: Smoking can increase the risk of ischemia.
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High Cholesterol: High cholesterol can lead to atherosclerosis which can cause colon ischemia.
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Clotting Abnormalities: Blood clotting disorders like sickle cell anemia can increase the risk.
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Reduced Blood Flow: Reduced blood flow due to diabetes, heart failure, shock, and rheumatoid arthritis can increase the risk.
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Surgery: Surgery involving the major artery that supplies blood from the heart to other parts of the body might sometimes cause a reduction in blood flow.
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Illicit Drugs: The use of cocaine and methamphetamines is most commonly associated with colon ischemia.
What Are the Symptoms of Colon Ischemia?
Symptoms can range from mild to severe, depending on the cause. The signs and symptoms of colon ischemia include:
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Abdominal tenderness or pain - any part of the colon can be affected, but colon ischemia mostly causes pain in the left side of the abdomen.
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Bloating.
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Blood in stool.
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Fever.
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Diarrhea.
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Nausea or vomiting.
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Lightheadedness.
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The urge to have a bowel movement or sudden forceful bowel movements.
What Is the Diagnosis of Colon Ischemia?
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Physical Exam: The doctor will ask about the symptoms and risk factors and do a physical examination. A physical examination is done to check for tenderness or pain in the abdomen.
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Blood Tests: A blood test reveals a high white blood cell count as a result of infection.
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Stool Test: Stool samples are collected and checked for bloody stool and infection.
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Endoscopy: The doctor inserts a thin, long, flexible tube attached to a camera to see the colon. Flexible sigmoidoscopy is inserted through the rectum to examine the lower part of the colon and colonoscopy uses a long tube to examine the entire colon.
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Computed Tomography (CT) Scan: This imaging test uses X-rays to create cross-sectional images of the colon, small intestine, and blood vessels.
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Magnetic Resonance Imaging (MRI): This imaging technique uses a magnetic field and radio waves to create more clear images of the intestines and abdominal organs.
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Angiogram: This is done only in severe cases. The doctor inserts a long thin tube into an artery in the groin and guides it into the aorta. A dye is injected which flows through the blood vessels of the intestine and the doctor takes x-rays of the blood flow.
What Is the Treatment for Colon Ischemia?
Treatment depends on the severity of the condition. The goal of the treatment is to restore the blood supply of the colon and to maintain the function of the digestive tract. In mild cases, the signs and symptoms usually diminish in two to three days.
The doctor might recommend:
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Antibiotics to treat the infection.
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Intravenous fluids to treat dehydration.
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A liquid diet is recommended.
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Avoid medications like migraine and hormone drugs.
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Treatment is done to treat underlying medical conditions like heart failure.
In severe cases, surgery is done to remove the dead tissue, repair the perforation, and remove the part of the colon that is narrowed and causing a blockage. Surgery is rarely needed. It is done if other treatments fail.
The surgery is done in two methods: the open method, in which the surgeon makes a large cut in the abdomen to repair the intestine, or to remove the dead tissue and restore the proper blood flow in the intestine by connecting the healthier parts. In the laparoscopic method, the surgeon makes several small cuts in the abdomen through which surgical tools and a laparoscope is inserted to remove blockages in the blood vessels and restore the blood flow. It is a minimally invasive procedure that has less pain and quicker recovery.
What Are the Complications of Colon Ischemia?
In severe cases, colon ischemia can lead to:
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Gangrene: Gangrene is tissue death due to reduced blood flow.
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Perforation: Perforation in the intestine leads to leakage of contents of the colon into the abdominal cavity or persistent bleeding from the intestine.
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Peritonitis: Perforation in the intestinal wall can lead to peritonitis, which is a serious infection, and inflammation of the abdominal lining.
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Bowel obstruction.
Conclusion:
Acute ischemic colitis is a medical emergency and requires treatment immediately. The condition goes away in two to three days with mild treatment. Only severe cases require surgery. The mortality rate is high if the death of tissue occurs in the colon.
