I am a 25 year old male with no problems in medical history. I am healthy and eat healthy. I have been having pain while passing stool on the left side of my rectum about an inch from the exterior of my anus. It feels like a needle is being pushed into my skin when I defecate. I have not seen blood in my stool or on the toilet paper, and there is little to no pain while sitting and not using the bathroom, only when I poop. I tried looking to see if there was anything noticeable and there seems to be (and I might be wrong) a little off colored spot where I am feeling pain, slightly redder than the surrounding tissue. Is this an anal fissure, ulcer, hemorrhoid, or something more serious? I am planning on seeing my doctor but would like your opinion as well.