Colitis is inflammation of the colon. Other parts of your intestines, which includes, the colon, may also be affected. If you have colitis, you will feel discomfort and pain in your abdomen. You symptoms maybe be mild and reoccur over a long period of time. Or you may suffer from severe symptoms that manifest quickly.

Types of Colitis

Colitis can be categorized by what causes it.

Ulcerative Colitis (UC)

UC is one of two conditions classified as inflammatory bowel disease. (The other is Crohns disease.) UC is a long-lasting disease that produces inflammation and bleeding ulcers in the inner lining of your large intestine. It generally begins in your rectum and spreads to the colon. UC is the most commonly diagnosed type of colitis. It occurs when your immune system overreacts to bacteria in your digestive tract, but experts do not know why this happens. Common types of UC include:

  • proctosigmoiditis, which affects the rectum and lower portion of the colon
  • left-sided colitis, which affects the left side of the colon beginning at the rectum
  • total colitis, which affects the entire large intestine

Pseudomembranous Colitis (PC)

This type of colitis occurs from overgrowth of the bacterium Clostridium difficile. Bacteria of this kind normally live in your intestine but do not cause problems because they are balanced by the presence of other, “good” bacteria. But taking certain medications may destroy healthy bacteria and allow Clostridium difficile to take over. The bacteria release toxins that cause inflammation.

Ischemic Colitis (IC)

Ischemic colitis occurs when blood flow to you colon is suddenly cut off or restricted. Blood clots are the most common reason for sudden blockage. Atherosclerosis, or the buildup of fatty deposits, in the blood vessels that supply your colon is usually the reason for recurrent IC. This type of colitis is sometimes the result of underlying conditions. These may include:

  • vasculitis (inflammation of the blood vessels)
  • hernia
  • diabetes
  • colon cancer
  • dehydration

Although it is rare, IC may occur as a side effect of taking certain medications.

Additional Causes

Other causes of colitis include infection from parasites, viruses, and food poisoning from bacteria. You may also develop the condition if your large intestine has been treated with radiation.

Who Is at Risk for Colitis?

Different risk factors are associated with each type of colitis.

You are more at risk for ulcerative colitis if:

  • you are between the ages of 15 and 30 (most common) or 60 and 80
  • you are of Jewish or Caucasian descent
  • you have a family member with UC. This type tends to run in families. Some research has demonstrated that certain abnormal genes are often present in those with UC (NIDDK)

You are more at risk for pseudomembranous colitis if:

  • you are taking antibiotics
  • you are hospitalized
  • you are receiving chemotherapy
  • you are taking immunosuppressants
  • you are older
  • you have had PC before

You are more at risk for ischemic colitis if:

  • you are over age 50
  • you have or are at risk for heart disease
  • you have heart failure
  • you have low blood pressure
  • you have had an abdominal operation

What are the Symptoms of Colitis?

Depending on your condition, you may experience one or more of the following symptoms:

  • abdominal pain or cramping
  • bloating in the abdomen
  • weight loss
  • diarrhea
  • blood in your bowel movements
  • urgent need to move your bowels
  • chills and/or fever
  • vomiting

Diagnosing Colitis

Your physician may ask about the frequency of your symptoms and when they first occurred. He or she will perform a thorough physical exam and use diagnostic tests such as:

  • colonoscopy—a camera on a flexible tube is threaded through the anus to view the rectum and colon
  • sigmoidoscopy—similar to colonoscopy but shows only the rectum and lower colon
  • stool samples
  • abdominal imaging such as magnetic resonance imaging (MRI) or computed tomography (CT) scans
  • barium enema—an X-ray of the colon after it is injected with barium, which helps make images more visible

Treating Colitis

Treatments vary by the type of colitis you have, your age, and overall physical condition.


Anti-inflammatory medication may be used to treat swelling and pain, and antibiotics can treat infection.


Surgery to remove part or all of your colon and/or rectum may be necessary if other treatments do not work.

What Is to Be Expected in the Long Term?

Your outlook depends on the type of colitis you have. Ulcerative colitis may require lifelong medication therapy if surgery is not done. Other types, such as ischemic colitis, usually improve without surgery. Pseudomembranous colitis generally responds well to antibiotics but may recur.

In all cases, early detection is critical to your success. Report any signs and symptoms to your physician. Early detection may help prevent other serious problems such as colon cancer.