1. Groton, Marcia MSN, RN
  2. Fisher, Michael J. MD, FACG
  3. Speroni, Karen Gabel BSN, PhD, MHSA, RN
  4. Daniel, Marlon G. MPH


Colorectal cancer, the third most common cancer in U.S. adults, can be detected early through colonoscopy. Thorough bowel preparation facilitates successful colonoscopy. Effectiveness, tolerability, and costs of 3 bowel preparations were compared in patients undergoing outpatient screening colonoscopy. In this prospective, randomized, single-blind study, comparing three preparation protocols, 209 of 276 consented subjects completed (Protocol [N = 67] = HalfLytely(C) 1 L x 2 doses and bisacodyl 5 mg delayed release tablets x 2 tablets; Protocol 2 [N = 74] = MiraLAX(R) 5 tablespoons x 2 doses and bisacodyl 5 mg tablets x 2 tablets; and Protocol 3 [N = 68] = MoviPrep 1 L x 2 doses). Patients completed symptom diaries and a gastroenterologist rated effectiveness. Most subjects were White females, aged 59 years (mean). Protocol 1 was the most effective regimen, but Protocol 2 was the most tolerable and cost-effective. While the three bowel protocol differences were not statistically significant for all outcomes measured, there were clinically meaningful differences. As Protocol 1 was most effective, HalfLytely(C) and bisacodyl is recommended for patients prior to colonoscopy. For patients who cannot tolerate HalfLytely(C) or MoviPrep, or with financial concerns, Protocol 2 (MiraLAX(R) & bisacodyl) is alternatively recommended.