Is Early or Late Colonoscopy Optimal for Acute Lower Gastrointestinal Bleeding?

Internal view of the intestinal walls. Colonoscopy is the endoscopic examination of the large bowel and the distal part of the small bowel with a camera on a flexible tube. 3d render
Researchers sought to determine if early vs late colonoscopy would be optimal timing among patients with hematochezia.

Although early colonoscopy increased the identification of stigmata of recent hemorrhage (SRH) and resulted in shorter length of hospital stay among patients with acute lower gastrointestinal bleeding (ALGIB), it increased the rebleeding rate and did not improve mortality or the requirement for interventional radiology (IVR) or operation, according to study results published in Gastrointestinal Endoscopy.

For the retrospective, multicenter cohort study, researchers identified 10,342 individuals with acute hematochezia who were admitted to hospitals in Japan. A total of 6270 patients who underwent colonoscopy within 120 hours of ALGIB presentation were included in the study.

Adjustments for baseline characteristics were performed using inverse probability of treatment weighting. Patients were stratified by early (≤24 hours; 66%), elective (24-48 hours; 18%), and late (48-96 hours; 16%) colonoscopy groups. The primary outcome was 30-day rebleeding. Secondary outcomes included SRH identification rate, the requirement for corrective IVR or operation, the length of hospital stay, and 30-day mortality.

In the early group, the rate of SRH identification was significantly higher than in both the elective (odds ratio [OR], 1.785; 95% CI, 1.521-2.094) and late (OR, 2.562; 95% CI, 2.089-3.143) groups. Length of stay was also shorter in the early vs elective (-0.820; 95% CI, -1.504 to -0.136) and late (-1.296; 95% CI, -2.041 to -0.552) groups. The rate of 30-day rebleeding was significantly higher in the early group compared with the elective (OR, 1.347; 95% CI, 1.119-1.622) and late (OR, 2.259; 95% CI, 1.752-2.914) groups. No significant intergroup differences in IVR or operation requirement or 30-day mortality were observed. A significant interaction with the heterogeneity of effects was identified between early vs late colonoscopy and both performance status (PS) (PS 0-2: OR, 2.481; PS ≥3: OR, 0.458; P =.022) and shock index (shock index <1: OR, 2.097; shock index ≥1: OR, 1.095; P =.038) for 30-day rebleeding. The requirement for IVR or operation among those who underwent early colonoscopy was significantly lower in those with a shock index of at least 1 (OR, 0.267; 95% CI, 0.099-0.721) than in those given a late colonoscopy.

Limitations to this study include a retrospective and observational design, as well as potential unmeasured confounders and the inclusion only of individuals who received colonoscopy.

“We have demonstrated that early colonoscopy improved SRH identification and shortened the length of stay,” the study authors wrote. “However, early colonoscopy was associated with higher 30-day rebleeding rate and did not improve IVR/surgery requirement or mortality. Early colonoscopy was beneficial for those with a shock index ≥1 or PS ≥3. Therefore, most ALGIB patients do not need to receive colonoscopy immediately, rather, vitals and PS can be an indication of the requirement for early colonoscopy.”


Shiratori Y, Ishii N, Aoki T, et al. Timing of colonoscopy in acute lower gastrointestinal bleeding: a multicenter retrospective cohort study. Gastrointest Endosc. Published online August 2, 2022. doi:10.1016/j.gie.2022.07.025