Thank you to Geoff for presenting the case of an elderly woman with history of hypothyroidism p/w lightheadedness/presyncope found to have a bloody BM with BPs in the 80s systolic. After work-up and imaging she was found to have wall thickening of the recto sigmoid flexure c/f ischemic colitis.
- When admitting a patient with a potential GI bleed describe the stool as brown, melena or bloody (red). Smear the stool on a white paper towel to help identify the color. Our GI colleagues recommend against using a Guaic test!!
- Severe pain is more likely for acute ischemia involving the small bowel compared with the colon, for which extreme pain is usually not as prominent a feature.
- See the management flow chart from uptodate for ischemic colitis
- Major society guidelines suggest empiric broad-spectrum antibiotics (such as ertapenem) for most patients with moderate to severe colonic ischemia despite lack of strong evidence to support use.
- The image below of the blood supply to the colon and rectum can help you identify watershed areas (at risk areas for ischemia).
Differential Diagnosis we discussed for Etiologies of Colonic Ischemia
- Mesenteric venous thrombosis
- Small vessel disease – Vasculitis, amyloidosis or radiation
- Global shock – especially in watershed areas (see photo below)
- Mechanical Obstruction – malignancy, hernia or adhesions
- Hematologic abnormalities – hypercoagulable, sickle cell
- Surgical – aortoiliac bypass
- Drugs – cocaine, NSAIDs, diuretics
- Others: long-distance running, infectious (CMV, E. Coli O157:H7)
Bonus Outpatient Pearl
An Italian study assessed the 12 year performance of biannual fecal immunochemical testing (FIT) testing, finding that patients seem to do as well as with primary colonoscopy screening. See study attached here for more information.
Zorzi M, Hassan C, Capodaglio G, et al Long-term performance of colorectal cancer screening programmes based on the faecal immunochemical test Gut Published Online First: 03 November 2017. doi: 10.1136/gutjnl-2017-314753