The laboratory findings in a patient with ulcerative colitis include anemia, low albumin, elevated ESR, elevated serum alkaline phosphatase, deranged LFTs and electrolyte abnormalities.^[1][2]

The initial diagnostic workup for ulcerative colitis includes the following:^{[3][4][1][2][5][6]}

• A complete blood count shows
  • Anemia
  • Thrombocytosis
  • A high platelet count
• Elvated ESR (>30mm/hr)
• Low albumin
• Electrolyte studies and renal function tests are done, as chronic diarrhea may be associated with
  • Hypokalemia
  • Hypomagnesemia
  • Pre-renal failure
• Liver function tests are performed to screen for bile duct involvement: primary sclerosing cholangitis.
• Fecal lactoferrin or calprotectin may be checked to depict intestinal inflammation
• Urinalysis
• Elevated serum alkaline phosphatase (in case of uc and psc)
• Stool culture, to rule out parasites and infectious causes.
• C-reactive protein can be measured, with an elevated level being another indication of inflammation.

Although ulcerative colitis is a disease of unknown causation, inquiry should be made as to unusual factors believed to trigger the disease.^[4] Factors may include: recent cessation of tobacco smoking; recent administration of large doses of iron or vitamin B6; hydrogen peroxide in enemas or other procedures.