The pathogenesis remain unknown. Inflammation is localized primarily in the mucosa. The most common symptoms are abdominal pain, rectal bleeding, diarrhea, fever, and malaise. The incidence ranges from 4 to 15 cases per 100,000. Disease may present at any time but does so most often Extraintestinal manifestations Musculoskeletal.
Arthritis is the most common extraintestinal manifestation of ulcerative colitis.
It is migratory, often involving the hip, ankle, wrist, or elbow. It is usually monoarticular and asymmetric, and Ocular. Episcleritis, uveitis, and iritis may Dermatologic. Abnormalities may include erythema nodosum, pyoderma gangrenosum, lichen planus, and aphthous ulcers. Other complications include nephrolithiasis and a hypercoagulable state.