Screening for colorectal carcinoma

Dear Ask The Doctor: I have had a cut inside my anus for just over 20 years; at least that's what my then doctor told me. If my stool were hard I run the risk of bleeding, sometimes accompanied by excruciating pain; the blood would be fresh and could be dripping, and the following time I run the risk of being further injured from the hardened darkened blood inside. When this happens, it could take a few days before the episode is behind me. Once in a while it would come back now and again. This use to happen with regular frequency of may be once every 1-2 months. I have noticed in the last 5 years or so, the frequency has gone down. I am concerned if I am therefore more likely to develop colon cancer. I use Preparation H or Anusol, to soften the stool if I feel one coming, or that it has hardened to a point that it would hurt. I would use it before and during each episode, as necessary. What should I do? Would a colonoscopy reveal anything? I understand that folks over 50 should get a colonoscopy regularly, I am now 46. Thanks, Mitch

Dear Mitch: I can find no evidence to suggest that an anal tear increases your risk of colorectal carcinoma. Although any source of chronic inflammation has the potential to develop malignant cells. Methods of screening include: tests that can detect cancers at an early treatable stage (stool tests, faecal occult blood testing), and tests that also detect adenomas and so lead to cancer prevention (structural examination of the colon, sigmoidoscopy, or colonoscopy). If the anal tear has completely resolved a simple faecal occult blood test may be sufficient screening and this can be organised by your family practitioner.