Ulcerative colitis

What is ulcerative colitis?

Ulcerative colitis is a long-term inflammatory bowel disease in which the immune system inflames the lining of the colon and rectum. It starts in the rectum and spreads continuously along the colon, forming small ulcers that produce blood, pus and mucus. The extent of disease varies and guides treatment.

Inflammation affects the surface lining of the colon in a continuous area rather than patches. The disease is classified by how much of the bowel is involved.

What causes ulcerative colitis?

The exact cause of ulcerative colitis is unknown. It involves an abnormal immune reaction against the lining of the colon in people with a genetic susceptibility, with environmental triggers and gut bacteria contributing. It is not an infection and cannot be passed on to other people.

• An immune reaction against the colon lining
• Genetic susceptibility
• Environmental triggers
• Gut bacteria contributing to inflammation

What are the symptoms?

Ulcerative colitis typically causes diarrhoea with blood and mucus, an urgent need to open the bowels and abdominal pain, which come and go as flares. Tiredness and anaemia are common. In severe attacks, people also have fever, weight loss and many bloody stools each day.

• Bloody diarrhoea with mucus
• Urgent need to open the bowels
• Abdominal pain
• Tiredness and anaemia
• Weight loss and fever in severe cases

When should I see a colorectal surgeon?

See a doctor about possible ulcerative colitis if you have blood in your stool or diarrhoea lasting more than a few weeks. Go to an emergency department for a severe attack with many bloody stools a day, fever, a swollen or painful abdomen, dehydration, heavy bleeding, or symptoms that do not respond to treatment.

The warning signs below need prompt attention.

• A severe attack with many bloody stools
• A swollen or painful abdomen
• Fever and dehydration
• Heavy bleeding
• Symptoms that do not respond to treatment

How is it diagnosed?

Ulcerative colitis is diagnosed with a colonoscopy or flexible sigmoidoscopy that shows continuous inflammation starting in the rectum, with biopsies taken to confirm it. Stool tests rule out infection, and blood tests check for anaemia and inflammation. Imaging is used in severe attacks.

• Colonoscopy with biopsies
• Stool tests to rule out infection
• Blood tests and anaemia checks
• Imaging in severe attacks

How is ulcerative colitis treated?

Ulcerative colitis is treated with anti-inflammatory medicines, including suppositories for rectal disease, steroids for flares, and immune or biologic therapy. Surgery to remove the colon and rectum is used for severe attacks, heavy bleeding, a precancerous change, or disease that medicine cannot control. It removes the disease itself.

• Anti-inflammatory medicines and suppositories
• Steroids for flares
• Biologic and immune therapy
• Surgery to remove the colon and rectum when needed
• Cancer surveillance with colonoscopy in long-standing disease

What are the risks and complications?

Severe ulcerative colitis can cause heavy bleeding, severe swelling of the colon and rupture of the bowel. Long-standing extensive disease raises the risk of bowel cancer, which is why surveillance colonoscopy is offered. Surgery carries its own risks and may involve a pouch or a stoma.

• Severe swelling of the colon
• Heavy bleeding
• Rupture in a severe attack
• Higher long-term cancer risk with extensive disease
• Surgery and, in some operations, a pouch or stoma