Peppermint oil for flexible sigmoidoscopy pre-medication

Interventions: All attenders at a flexible sigmoidoscopy based colorectal cancer screening group are invited to participate in this substudy. Participants are randomly allocated to receive a peppermint oil capsule taken orally at least 30 minutes prior to undergoing sigmoidoscopy. Additionally, the same participants are randomly allocated to recieve one (standard care) or two phosphate enemas per rectum as bowel preparation also at least 30 minutes prior toprior to sigmoidoscopy. Both interventions are single administrations only on the day of sigmoidoscopy.
Primary outcome(s): Adenoma detection rate at sigmoidoscopy. Polyp detection is determined immediately at sigmoidoscopy.Pathology reports 5-7 days later are obtained to determine if the polyp was adenomatous.[]
Study Design: Purpose: Treatment; Allocation: Randomised controlled trial; Masking: Blinded (masking used);Assignment: Parallel;Type of endpoint: Efficacy