Can’t help you too much, as I was not really in any pain at all (and I’m a big baby) after my operation, but I did piss some big blood clots of old, brown blood, around four weeks after my surgery.
I rationalised it by by comparing the state of healing of my seven post-operative puncture wounds, and assumed the internal healing was at a similar stage. The abdominal wounds took months to heal properly.
Cheers, John.