[Is rigid rectoscopy obsolete?].
Flexible fiberoptic sigmoidoscopy more and more replaces sigmoidoscopy with a rigid tube. In a retrospective series of 152 rigid sigmoidoscopies we analysed depth of endoscopy and findings. In 36% of patients without anaesthesia endoscopy had to be stopped at 15 cm and in further 31% at 20 cm leading to a highly significant difference to the anesthetized patients (p less than 0.0005). A good history of the present illness allows separating of bleeding carcinoma and polyps proximal to the sigmoid colon which have to be examined by colonoscopy. In routine screening for blood loss per anum it is desirable to achieve in all patients a maximal security not to overlook a finding, because of the medical costs. We have enlarged the list of indications for the rigid sigmoidoscopy by Marks et al. as a practical compromise: delineation of rectal lesions, side localization and critical rectal measurements, surveillance of disease states or anastomoses within its reach, for performing rectal biopsy and rectal polypectomy, in patients with possible contamination of the instrument, endoscopy in the anesthetized patient before a proctological operation if case history excludes a higher sited lesion. In all other cases there is an indication for colonoscopy or barium contrast enema. It is stressed that in patients with blood loss per anum the search for the source always is done by flexible fiberoptic sigmoidoscopy.