Last reviewed 01/2018

  • FBC - anaemia due to blood loss; leukocytosis

  • ESR - increased; correlates with active disease

  • CRP - raised; but less so than in Crohn's disease

  • biochemistry - in active disease, biochemical abnormalities may include hypokalaemia, hyponatraemia, hypomagnesaemia, hypocalcaemia, and hyoalbuminaemia. Abnormal LFTs due to associated chronic active hepatitis - increased ALT - or sclerosing cholangitis - increased alkaline phosphatase

  • ANCA - found in HLA-DR2 associated form of ulcerative colitis

  • radiology:
    • plain abdominal x-ray - excludes toxic dilatation, which is more than 5.5 cm in diameter in adults
    • barium enema:
      • diagnosis of extent and severity of the disease
      • procedure is contraindicated in those patients at risk of a toxic dilatation

  • rectal biopsy - taken at sigmoidoscopy

  • colonoscopy - this is contraindicated in those patients at risk of toxic dilatation. Allows multiple biopsies to be taken throughout the colon and delineation of the extent and activity of the disease

  • white cell scan - allows imaging in severe disease

  • molecular biology - a high intensity of CD44v6 and v3 epitope expression on crypt epithelial cells in patients with UC has been noted. This observation may have diagnostic potential in distinguishing UC from Crohn's