Pain and bleeding. Rectal pain and bleeding is usually a fissure. Internal hemorrhoids usually bleed painlessly and external hemorrhoids usually hurt and don't bleed. If the fissure is chronic, present for more than a couple of months, the pain and bleeding may resolve but that does not mean the fissure is gone. Have an expert examine to confirm actual healing of the fissure once symptoms resolve.
Severe pain. Anal fissure is a small crack in the anal canal next to tail bone, gives severe pain spasm, aggravates during defaecation, with small amount of bright blood. From out side you can see a small skin tag next to tail bone called sentinal hemorroid. Most of the time they heal with out surgery, by local care diet, and may need pain medications.
Pain with BM. Painful bm with or without blood in stool. It would take a doctor to see the actual cut in the rectum to diagnose it.
Physical exam. An examination with a doctor can visualize the tear in the anal skin (fissure). You cannot see it yourself.