The Safety and Efficacy of Methylene Blue MMX® Modified Release Tablets Administered to Subjects Undergoing Screening or Surveillance Colonoscopy

Inclusion Criteria: * Males or females, aged between 50 and 75. * Outpatients scheduled for screening or surveillance colonoscopy for polyps or colorectal cancer ) * Able to comprehend the full nature and purpose of the study, including possible risks and side effects. * Able to co-operate with the investigator and to comply with the requirements of the entire study. * Signed written informed consent prior to inclusion in the study. Exclusion Criteria: * Patients at high risk of colorectal cancer e.g. ulcerative colitis * Previous medical history of, or suspected hypersensitivity to, the Methylene Blue and/or formulations' ingredients. * Previous medical history of, or suspected hypersensitivity to, the PEG based bowel cleansing preparation and/or bowel cleansing formulations' ingredients. * Previous medical history of gastrointestinal obstruction or perforation, toxic megacolon, major colonic resection, severe diverticulitis, heart failure (Class III or IV), serious cardiovascular disease, ulcerative colitis or Crohn's disease.