Overview

The severity of ulcerative colitis is determined by certain criteria.^{footnote 1} Ulcerative colitis can be classified as mild, moderate, severe, or fulminant (very severe), which may guide treatment choices.

People who have mild ulcerative colitis may have:

• Fewer than four bowel movements (stools) a day.
• No bleeding or a small amount of bleeding with stools.
• Normal erythrocyte sedimentation rate (ESR).

People who have mild ulcerative colitis do not have fever, rapid heartbeat, or anemia.

People who have moderate ulcerative colitis may have:

• More than four stools a day.
• Mild elevation in ESR.

People who have severe ulcerative colitis may have:

• More than six bloody stools a day (loose stools).
• Fever, rapid heartbeat, and anemia.
• An elevated ESR.

People who have fulminant ulcerative colitis may have:

• More than 10 stools a day (loose stools).
• Constant bleeding from the rectum.
• Fever, rapid heartbeat, and anemia.
• Cramping belly pain and bloating.
• An expanded colon (as seen on an X-ray).
• A need for blood transfusions.

Flare-ups can be so severe that they require hospitalization.