What is a proctosigmoidoscopy?

This procedure uses a proctoscope, sigmoidoscope, or colonoscope and digital examination to evaluate the lining of the distal sigmoid colon, rectum, and anal canal. It's indicated in patients with recent changes in bowel habits, lower abdominal and perineal pain, prolapse on defecation, pruritus, and passage of mucus, blood, or pus in the stool. Specimens may be obtained from suspicious areas of the mucosa by biopsy, lavage or cytology brush, or culture swab.

This is a more clinical answer than I was hoping to give you. The above is obtained from

Medical-clinic.org

This is a more professional site but a great place to start with questions regarding preps, expectations and other facts that could prove to be helpful to you.

Hope this helps.