Ischemic Colitis

Background: Decreased perfusion and resulting ischemia of colon - at risk due to vascular supply from superior mesenteric artery, inferior mesenteric artery, internal iliac arteries —> creates watershed areas at splenic flexure and rectosigmoid junction

3 Main Classifications:

• Hypoperfusion - most common cause

• Acute arterial occlusion (embolic, thrombotic)

• Venous thrombosis of mesenteric vein - more commonly implicated in acute mesenteric ischemia

Risk Factors:

• Cardiovascular disease

• Dialysis

• Drugs - cocaine, amphetamines, immune modulators, constipation-inducing (opioids, anti-motility agents), many others

• Thrombophilia

• Aortic procedures

• Extreme exercise (due to shunting)

Signs/symptoms:

• Lower abdominal pain —> tender to palpation with voluntary guarding (more indolent onset in comparison to acute mesenteric ischemia)

• Rectal bleeding

• Diarrhea

Diagnosis:

• Obtain CT A/P with IV contrast +/- PO contrast

• Confirmation usually with colonoscopy within 48 hours

• Labs - BMP, CBC, coags; often will have elevated WBC and lactate (in setting of hypo-perfusion) although non-specific

Management:

• Conservative in most - IV fluids, broad spectrum antibiotics, keep NPO

• 20% require surgical intervention, higher mortality in this group

Complications:

• Hemorrhagic shock

• Sepsis

• Necrotic bowel

• Stricture formation

References:

Azam, B et al. Ischemic colitis. J Emerg Med. 2019 May;56(5):e85-e86.

Brandt LJ, Feuerstadt P, Longstreth GF, et al. ACG clinical guideline: epidemiology, risk factors, patterns of presentation, diagnosis, and management of colon ischemia (CI). Am J Gastroenterol 2015; 110:18.

Trotter J M, Hunt L, Peter M B. Ischaemic colitis BMJ 2016; 355 :i6600