Background Ischemic colitis (IC) is a known significant complication after repair of a ruptured abdominal aortic aneurysm (rAAA). Lower endoscopy (colonoscopy or flexible sigmoidoscopy) is a helpful adjunct to aid decision making for surgical exploration. We believe routine use of lower endoscopy after rAAA repair provides better patient care through expeditious diagnosis and surgical care. Methods We performed a retrospective chart review of rAAA repairs from 2008 to 2019. All patients undergo screening lower endoscopy after rAAA repair at our institution. The incidence of IC, mortality, and diagnostic characteristics of routine lower endoscopy was analyzed. Results Of these, 182 patients underwent rAAA repair, among which 139 (76%) underwent routine lower endoscopy. Ischemic colitis of any grade was diagnosed in 25% of patients. The 30-day mortality was 11% compared to 19% in those without lower endoscopy. The presence of IC portended a 4-fold increase in mortality rate compared to those without (26% vs 6%, P = .005). Surgical exploration rate was 8% after routine lower endoscopy. Grade III ischemia on lower endoscopy had a sensitivity of 50% (95% CI 12-88) and specificity of 99% (95% CI 94-100) for transmural necrosis. Discussion We found increased incidence of IC and reliable diagnostic characteristics of routine lower endoscopy in predicting the presence of transmural colonic ischemia. There was decreased mortality with use of routine lower endoscopy but this was not statistically significant.