Ulcerative Colitis (UC)

The causes are still not fully understood. Ulcerative colitis is thought to result from an inappropriate immune response in genetically predisposed people, due to a complex interaction between environmental factors, microbes and the intestinal system.

Ulcerative colitis is a non-transmural inflammatory disease (it does not affect the full thickness of the wall), limited to the colon. It always affects the rectum and extends to a varying extent up the colon, at most affecting the whole colon (pancolitis). Extra-digestive manifestations include: uveitis, mouth ulcers, arthritis and polyarthritis, erythema nodosum, and primary sclerosing cholangitis.

The main symptom is persistent diarrhea with mucus and blood, often at night and after meals, sometimes with abdominal pain. When only the rectum is affected (proctitis), rectal bleeding and rectal symptoms predominate.

Colonoscopy with ileoscopy is the key examination for diagnosis. It confirms the diagnosis, determines the extent and severity of the disease, rules out other conditions and allows biopsies to be taken.

Ulcerative colitis progresses in flare-ups separated by periods of remission. After a first flare-up, 95% of patients will relapse within 20 years. 20 to 30% of patients will eventually need surgery: colitis resistant to medical treatment, cancer or high-grade dysplasia, or severe acute colitis resistant to treatment.

Medical treatment includes several therapies:

• Salicylates
• Systemic corticosteroids
• Immunosuppressants: azathioprine, 6-mercaptopurine
• Anti-TNF agents: infliximab, adalimumab…
• Monoclonal antibodies: vedolizumab

The reference surgical treatment remains total proctocolectomy with ileal pouch-anal anastomosis.