The present invention provides a speculum for performing colonoscopy in combination with colon irrigation/cleansing, a compact system comprising a colon irrigation device and a colonoscopy device, and a method for performing colonoscopy along with colon irrigation/cleansing. The present invention also provides a disposable kit with the speculum and a washer cone. The speculum according to the present invention comprises a main tube having a proximal end and distal end, and an inlet tube and an outlet tube intersecting to the main tube. The speculum of the present invention allows carrying out colonoscopy screening immediately following the colon irrigation which saves time.
