Agents indicated for cleansing of the colon as a preparation for colonoscopy (bowel preps) are among the most frequently prescribed drugs for otherwise healthy patients. Better bowel preparation has been shown to translate into higher adenoma detection rates. Therefore, safety and efficacy standards need to be high. Clinical trials can be designed to show superiority or non-inferiority, and there are 3 different types of relevant New Drug Applications. Current endpoint instruments rely on clinician reporting, and more than 1 endpoint instrument may be required to ensure a valid appraisal of efficacy. Future trials that study hard-to-prepare patients and populations who are potentially at higher risk for adverse events (eg, those with renal dysfunction) would be of interest. Orthostatic hemodynamic changes with bowel preps as a drug class occur more frequently than previously recognized, and this also deserves further study.
Keywords: cancer screening; clinical trial; experimental design; non-inferiority trial; outcome measures; phase 3; quality improvement.