The rigid sigmoidoscope has lost a great deal of value in specialist practice since the advent of the modern video-colonoscope. In general practice however, it is especially useful with the younger patient who is bleeding per rectum. An eyepiece prevents escape of air.
Disposable models are available.
It can of course be used under other circumstances, but it must be realised that polyps and cancers become more common over the age of 35 and that the failure to diagnose these conditions above the range of the rigid sigmoidoscope would be serious both for the patient and the doctor. As a routine prior to ano-rectal procedures. In the investigation of inflammatory rectal disease. To obtain biopsy specimens of any bowel condition within the reach of the instrument.