Ulcerative colitis (UC) is a chronic inflammatory and ulcerative disease arising in the colonic mucosa, characterised most often by bloody diarrhea.
Extraintestinal symptoms, particularly arthritis, may occur. Long-term risk of colon cancer is high. Diagnosis is by colonoscopy. Even though Crohn’s disease and ulcerative colitis are similar, they can be distinguished in most cases.
Laboratory tests should be done to screen for anaemia, hypoalbuminemia, and electrolyte abnormalities. Liver function tests should be done; elevated alkaline phosphatase and gamma-glutamyl transpeptidase levels suggest possible primary sclerosing cholangitis (PSC).
Perinuclear antineutrophil cytoplasmic antibodies, pANCA for short, are relatively specific (60 to 70%) for ulcerative colitis. Anti-Saccharomyces cerevisiae antibodies, or: ASCA, are relatively specific for Crohn’s disease. However, these tests do not reliably separate the two inflammatory bowel diseases (IBD).
Other possible laboratory abnormalities include leukocytosis, thrombocytosis, and elevated acute-phase reactants, such as erythrocyte sedimentation rate (ESR), and/or C-reactive protein (CRP).