BACKGROUND AND STUDY AIM: The study compared the efficacy of bowel cleansing using a low-volume mixed preparation (15 mg bisacodyl plus 2 L polyethylene glycol [PEG] solution) versus a standard high-volume preparation (4 L PEG) in patients with previous colorectal resection. PATIENTS AND METHODS: A total of 120 patients with prior colorectal resection for cancer undergoing surveillance colonoscopy were randomized to receive either a split-dose low-volume (n = 60) or high-volume (n = 60) preparation for bowel cleansing. The quality of bowel preparation, rated according to a modified Ottawa Bowel Preparation scale (mOBPS), represented the primary outcome measure. Tolerability, safety, and lesion detection rates were secondary outcomes. RESULTS: No significant difference was observed between the low-volume and high-volume preparations in achievement of adequate cleansing (i. e. mOBPS ≤ 4; low-volume vs. high-volume group, 85.0 % vs. 81.7 %, P = 0.624). The low-volume preparation showed a higher success rate for cleansing of the right colon (P = 0.025); better tolerability in terms of intake of the whole amount of the preparation (P < 0.001) was also observed. According to the logistic regression analysis, the only predictors of unsuccessful cleansing were previous left colectomy (P = 0.012) and a longer elapsed time since the intervention (P = 0.034). Lesion detection rates were comparable between the groups. No serious adverse events were reported. CONCLUSION: A low-volume preparation is not inferior to a high-volume preparation for adequate bowel cleansing in patients with prior colorectal resection for cancer. If larger, multicenter, prospective studies confirm our findings, a low-volume preparation will represent a more tolerable option for such patients. TRIAL REGISTRATION NUMBER: ClinicalTrial.gov identifier NCT01887158.