Case 1: Diagnostic Testing

Excellent choice! Patient has bloody diarrhea with labs showing anemia, thrombocytosis, presence of fecal leucocytes and raised fecal calprotectin, which are all concerning for inflammatory bowel disease. Colonoscopy will allow for mucosal inspection and tissue sampling to help confirm the diagnosis and characterize extent and severity.

This isn’t an appropriate next test. While it can reveal intestinal wall thickening or masses, it does not eliminate the need for a colonoscopy and will expose the patient to radiation unnecessarily. If the clinical suspicion for right sided isolated ischemia was high, then a CT angiography would have been indicated. Try again!

This isn’t an appropriate next test. If a diagnosis of inflammatory bowel disease is confirmed on colonoscopy, and if features of Crohns disease are noted (skipped pattern, terminal ileal involvement, rectal sparing) then a MRE would be useful at that juncture to rule out small bowel disease. Try again!

This isn’t an appropriate next test. Serologic markers such as perinuclear antineutrophil cytoplasmic antibodies (pANCAs) may be found in up to 70% of patients with ulcerative colitis (UC), and combination of negative anti–Saccharomyces cerevisiaeantibodies (ASCA) with elevated pANCA levels have been proposed to facilitate establishing a diagnosis of UC. However since the pooled sensitivity of antibody testing for diagnosis of UC is low, the guidelines recommend against serologic antibody testing to establish or rule out a diagnosis of UC.

Excellent choice! Given the patient’s chronic blood loss anemia it is important to obtain iron studies and initiate repletion as needed

Reasonable choice! These inflammatory markers will not help confirm a diagnosis, but their levels can be trended to ascertain IBD response to therapy.