Can anyone tell me why I throb up inside for hours and hours after a BM? Sometimes it's worse than others. I try to sit in a hot tub after a BM but I'm not always at home to do so.

I don't think anyone here can diagnose you based on a web post. Two likely possibilities are anal fissure and hemorrhoids, but if you are posting here, you already knew that. If it hurts like he11 while you are pooping, its probably a fissure. Pain after a BM with a fissure is due to the wound being irritated and to the walls of the sphincter spasming in pain.

I wasn't necessarily looking for a specific diagnosis...more for ideas based on what others are going through/have gone through.

I suggest you read the sticky "I have AF" at the top of the general section. It has lots of good information. Most people around here get some kind of spasm.