High resolution Anoscopy or HRA is a procedure that allows for examination and evaluation of the anal canal. Using a small thin round tube called an anoscope, the anal canal is examined with a high resolution magnifying instrument called a colposcope. Application of a mild acidic liquid onto the anal canal facilitates evaluation of abnormal tissue such as anal dysplasia. If indicated, a biopsy can be obtained. A digital rectal examination is also done at the time of the procedure. Pre-cancerous lesions (high grade intraepithelial neoplasia, AIN 2 or AIN 3) or carcinoma-in-situ can be treated with Infrared Photocoagulation in the office so that they do not become invasive cancer, which is more involved to treat. The procedure is performed in the office and generally lasts about 15 minutes. It is usually very well tolerated with mild if any discomfort. Significant risks such as bleeding or infection are extremely rare. Note should be taken that high resolution anoscopy is very different from colonoscopy or flexible sigmoidoscopy, neither of which can adequately exam the anal canal for the problems being detected by HRA. No bowel prep is needed for this examination. This service is available at RCRS.