Hi Thanks for posting on HCM CAT scan may reveal mostly organic abnormalities.Functional problems that may give you such symptoms may not be revealed by CAT scan.Possible though rare causes may include: -Anal itching -Coccydynia or coccygodynia (tailbone pain) -Levator ani syndrome (spasm in the muscles that surround the anus) -Proctalgia fugax These possible causes may not be revealed by your scan. I will suggest you try the following measure. *Eating more fruits, vegetables and whole grains, exercising daily, and taking stool softeners *You may use anti-hemorrhoid suppositories containing anesthesia if the pain too serious. * Over the counter pain drugs like ibuprofen may also help If pain persist with these measures, you see a Gastrologist for evaluation. Hope my answer will help you Best regards