Table of Contents
- Colitis definition and facts
- What is colitis?
- Colitis and the anatomy of the colon
- What are the causes (types) of colitis?
- Infectious causes of colitis
- Ischemic causes of colitis
- Inflammatory bowel disease and colitis
- Microscopic colitis
- Allergic colitis in infants
- What are colitis symptoms and signs?
- When should someone contact a doctor about colitis?
- What kind of doctor treats colitis, and how is it diagnosed?
- How is colitis diagnosed (physical examination)?
- What blood tests and/or stool samples diagnose colitis?
- What imaging tests and procedures diagnose colitis?
- What is the treatment for colitis?
- What is the prognosis for a person with colitis?
Ischemic causes of colitis
The colon can be thought of as a hollow muscle. It requires a normal blood supply to deliver oxygen and nutrients for the muscle to function normally. When the colon loses its supply of blood and becomes ischemic (isch= restricted + emia=blood supply), it may become inflamed. Ischemia or lack of blood supply causes inflammation of the colon leading to pain, fever, and diarrhea (bowel movements may contain blood).
- As a person ages, the arteries that supply blood to the colon gradually narrow and can cause ischemic colitis. Risk factors for narrowed arteries are the same as atherosclerotic heart disease, stroke, and peripheral artery disease (PAD). These include diabetes, high blood pressure, high cholesterol, and smoking.
- Ischemia caused bylow blood pressure or anemia (low red blood cell count) can decrease oxygen delivery to the colon.
- Patients who have atrial fibrillation (AFib) and are not anticoagulated are at risk for developing ischemic bowel. Small blood clots can form in the heart and embolize (travel) to block arteries that supply the colon with blood. This is the same mechanism that can cause a stroke in patients with AFib.
- The blood supply to the colon may be compromised when blood vessels are mechanically obstructed, for example by a twisting of the bowel (volvulus) or a herniation of the colon through openings in the abdomen wall (an incarcerated hernia).