Bad blood: ischemic conditions of the large bowel

Colon ischemia is the most common form of intestinal ischemic injury and is seen frequently in an elderly population. This disease is usually self-limited, and many causes have been identified. The recent literature has focused on estimates of prognosis, triaging appropriate level of care, and identification of optimal treatments. In this review, we will address our current understanding of colon ischemia including epidemiology, pathophysiology, segmental distribution, presentation, diagnosis, and management.

Research has recently been focused on factors associated with poor outcome. The medical comorbidities identified include chronic obstructive pulmonary disease (COPD), hepatic cirrhosis, and chronic aspirin use. Serological markers are noninvasive tools that can triage severity. Recent studies have shown procalcitonin, C-reactive protein, D-dimer, and neutrophil counts can help predict those at greatest risk for poor outcome. The timing of colonoscopy relative to symptomatic onset also can help predict severity. Early colonoscopy allows for quicker identification of ischemic stigmata, reducing the chance of misdiagnosis and potentially unnecessary and harmful treatment. The treatment of colon ischemia has classically been conservative with antimicrobials reserved for those with moderate or severe disease. Recent retrospective analysis calls into question the utility of antibiotics in the treatment of colon ischemia, although the data is not convincing enough to advise against antimicrobial treatment in patients with severe and fulminant disease.

It is an exciting time for research focused on colon ischemia. With an improved knowledge, awareness of associated risk factors and predictors of severity, clinicians now have enhanced clinical tools to diagnose and triage patients earlier in the disease. This should help institute prompt and appropriate therapies ultimately improving outcomes.