Diagnosis of ulcerative colitis

A gold standard method for diagnosis of Ulcerative Colitis is not currently available. However, diagnosis requires, at a minimum, negative stool culture and some form of sigmoidoscopy or colonoscopy. (1)

The diagnosis of ulcerative colitis is achieved through a combination of medical history, clinical evaluation and supported by the typical endoscopic and histological findings:

• proctosigmoidoscopy or colonoscopy with characteristic changes of ulcerative colitis (loss of the typical vascular pattern, granularity, friability, and ulceration)
• biopsy - to distinguish UC from infectious colitis
• negative stool examination - for infectious causes

Initial laboratory investigation methods for patients with active disease at presentation include:

• full blood count - may reveal thrombocytosis, anaemia, leucocytosis
• inflammatory markers (CRP or ESR)
• electrolytes
• liver function tests
• a stool sample for microbiological testing (1)

A number of autoantibodies especially perinuclear antineutrophil cytoplasmic antibodies (pANCA) have been identified in patients with UC. (approximately 50-60% of patients are found to be positive for pANCA). Due to the low sensitivity of pANCA for the diagnosis of UC it cannot be used as a diagnostic tool (1)

Reference

1. Rubin DT, Ananthakrishnan AN, Siegel CA, et al. ACG clinical guideline: ulcerative colitis in adults. Am J Gastroenterol. 2019 Mar;114(3):384-413.