Ulcerative colitis.

Abstract

Ulcerative colitis is a chronic relapsing and remitting disease in which chronic inflammation affects the rectum and extends proximally to a variable extent. The precise aetiology remains unknown but involves an interplay between reduced diversity in the gut microbiota and a genetically dysregulated gut immune system and epithelial barrier. Typical presentation of mild or moderate disease is with a gradual onset of symptoms including diarrhoea, rectal bleeding, and the passage of mucus. Severe disease is characterized by anorexia, nausea, weight loss, and severe diarrhoea, with the patient likely to look unwell with fever, tachycardia, and other signs of volume depletion, and the abdomen may be distended and tympanitic, with reduced bowel sounds and marked colonic tenderness. Diagnosis is usually made on the basis of exclusion of infective colitis by stool culture and the finding of typical diffuse inflammation in the rectum and above at sigmoidoscopy. Management requires rapid control of symptoms with induction therapy followed by maintenance of remission. Mild disease is typically treated with 5-aminosalicyclic acid delivered both orally and by enema, and moderate disease by 5-aminosalicyclic acid and steroids. Patients with severe disease require hospital admission, intravenous steroids, and daily review by both a physician and a surgeon experienced in the management of ulcerative colitis. Ciclosporin or infliximab are used as rescue therapies for steroid-resistant acute severe ulcerative colitis, but colectomy should not be delayed when this is required. Maintenance therapy with immunomodulators and biological therapies are both effective at maintaining remission, and several new biologicals are in clinical trials.