Inclusion Criteria:  Aged 18 years or over Be able to give voluntary, written informed consent to participate in the study  Exclusion Criteria:  Participants with symptoms that would make proctoscopic examination inappropriate, including acute anal fissure, symptomatic thrombosed haemorrhoids or obstructing anorectal lesions as determined by rectal examination Participants with a previous history of cancer Participants who have received previously radiotherapy, chemotherapy or immunotherapy for a malignancy.