Purposes: The long-term clinical course of outpatient-onset ischemic colitis remains unknown. Our aims are to elucidate the in- and out-of-hospital clinical outcomes of ischemic colitis and compare them with those of lower gastrointestinal bleeding (LGIB).
Method: A cohort of 370 outpatients was hospitalized for ischemic colitis (n = 57) or other LGIB (n = 313). All patients had undergone colonoscopy. During hospitalization, the need for transfusion or interventions, further bleeding, mortality, and length of hospital stay were measured. After discharge, long-term recurrence and mortality were analyzed by the Kaplan-Meier method.
Results: Colonoscopy revealed that 88% of ischemic colitis cases were left sided. Compared with other LGIB, ischemic colitis cases had significantly lower transfusion requirements (p < 0.01), further bleeding (p = 0.02), endoscopic intervention (p < 0.01), and shorter hospital stay (p = 0.03). No significant differences between the groups were noted in the need for surgery, angiographic procedures, or mortality during hospitalization. During a mean follow-up of 22 months, rebleeding was significantly lower (log-rank test; p < 0.01) in ischemic colitis cases (5.3%) than in other LGIB cases (19.4%) after discharge. During the mean follow-up period of 29 months, 1 patient (1.8%) with ischemic colitis and 18 patients (5.8%) with other LGIB died (log-rank test; p = 0.41).
Conclusions: Outpatient-onset ischemic colitis patients usually had left-sided colitis, recovered with conservative short-term treatment and had lower transfusion requirements and further bleeding compared with other LGIB patients. After discharge, patients with outpatient-onset ischemic colitis had lower recurrence over the long term than other LGIB patients.