Does anyone know why pain starts only 2 or 3 hours after having had a normal, painless, soft BM?

Spasms are like that, sadly, Tushi. You just never know when they are going to hit. The lack of blood flow to the area is one of the reasons for the intense pain. You can have a pain-free BM, but still the spasms can hit. I always use a Sitz Bath after my BMs. Bought at Rite Aid (tried different ones; happiest with their one).

Many thanks! It makes sense now!

Ya had a few good days this week, then today at around 11 am I felt like I sat on a cactus, that was 4 hours after a bm when I thought, hmmm, pretty good today will be okay.