Symptoms

Ulcerative colitis symptoms can vary, depending on how serious the inflammation is and where it happens. Symptoms may include:

• Diarrhea, often with blood or pus.
• Rectal bleeding — passing a small amount of blood with stool.
• Belly pain and cramping.
• Rectal pain.
• Urgency to pass stool.
• Not being able to pass stool despite urgency.
• Weight loss.
• Fatigue.
• Fever.
• In children, failure to grow.

Types

Healthcare professionals often classify ulcerative colitis according to its location. Types of ulcerative colitis include:

• Ulcerative proctitis. Inflammation is confined to the area closest to the anus, called the rectum. Rectal bleeding that sometimes happens with difficulty having bowel movements may be the only sign of the disease.
• Left-sided colitis. Inflammation extends from the rectum up through the sigmoid and descending colon. Proctosigmoiditis is a type of left-sided colitis. Inflammation involves the rectum and sigmoid colon — the lower end of the colon. Symptoms include bloody diarrhea, belly cramps and pain, and not being able to move the bowels despite the urge to do so, called tenesmus.
• Widespread colitis. This is sometimes called pancolitis. This type often affects the entire colon and causes bouts of bloody diarrhea that may be severe, belly cramps and pain, fatigue, and significant weight loss.

When to see a doctor

See a healthcare professional if you notice a lasting change in your bowel habits or if you have symptoms such as:

• Belly pain.
• Blood in the stool.
• Ongoing diarrhea that doesn’t respond to nonprescription medicines.
• Diarrhea that awakens you from sleep.
• An unexplained fever lasting more than a day or two.

Causes

The exact cause of ulcerative colitis isn’t known. Previously, diet and stress were suspected, but now healthcare professionals know that these factors may worsen but don’t cause ulcerative colitis. Possible causes may include:

• Immune system issue. One possible cause is an immune system malfunction. When the immune system tries to fight off an invading virus or bacterium, an irregular immune response causes the immune system to attack the cells in the digestive tract too.
• Genetic traits. Several genetic markers have been associated with ulcerative colitis. Heredity also seems to play a role in that the condition is more common in people who have family members with the disease.

Risk factors

Ulcerative colitis affects about the same number of women and men. Risk factors may include:

• Age. Ulcerative colitis usually begins before the age of 30. But it can occur at any age, and some people may not develop the disease until after age 60.
• Race or ethnicity. Although white people have the highest risk of the disease, ulcerative colitis can happen in any race. The risk is even higher for those of Ashkenazi Jewish descent.
• Family history. You’re at higher risk if you have a close relative, such as a parent, sibling or child, with the disease.

Complications

Possible complications of ulcerative colitis include:

• Severe bleeding.
• A hole in the colon, known as a perforated colon.
• Severe dehydration.
• Loss of red blood cells, known as anemia.
• Bone loss, called osteoporosis.
• Inflammation of the skin, joints and eyes.
• An increased risk of colon cancer.
• A rapidly swelling colon, called toxic megacolon.
• Increased risk of blood clots in veins and arteries.
• Delayed growth and development in children.