This will be a prospective multi-center, multi-national comparative non-blinded clinical investigation. Each subject will undergo back-to-back tandem colonoscopies with the Aer-O-Scope Colonoscope System and a conventional colonoscope since this is a tandem colonoscopy study, each subject will serve as their own control. The 1st procedure will be randomized, half to Aer-O-Scope Colonoscope System and half to conventional colonoscope. The same investigator will perform both procedures on each subject. All pathologies found will be either removed or tattooed. Unmarked pathologies found on second pass will represent those missed during the 1st pass, thus making the subject and the control one and the same. Tattooed pathologies that can be removed endoscopically will be removed in an additional colonoscopy. This may occur if a large polyp cannot be removed for any reason with the Aer-O-Scope, but can be removed with conventional colonoscopy.