Hi there.. I can understand your concern.. pain during or after anal intercourse is common..anal intercourse has health risks, because the anus is full of nerve endings, making it very sensitive. The anus lacks natural lubrication that vagina has. So Penetration can tear the tissue inside the anus, allowing bacteria and viruses to enter the bloodstream. This can result in the spread of sexually transmitted infections , anal warts. Using lubricants can help some, but doesn't completely prevent tearing. If your not involved in anal sex and yet have pain in anus after sex then it could be due to fissure in and or perianal or perineal abscess.. please consult nearby surgeon soon for complete examination..