After having some bowel problems, I had a colonoscopy, which showed that I have ulcers on my colon, approximately 30 cm in. Although the results of the biopsies taken during the colonoscopy and the stool cultures are still pending, my doctor told me I need to go to my gynecologist and get tested for gonorrhea and chlamydia. However, I was tested 3 years ago, and was negative, and have been in the same monogamous relationship since then. Also, I have never had anal sex. Could colon ulcers be caused by an STD in a person who has never had anal sex? I am skeptical, and I don't want to be tested again unless it is a real possibility.