HI Dowgirl,
I haven't had LIS but I have had other anal surgeries and it can cause spasming throughout your pelvic floor. That is why they always wait to release you until you urinate because an injury in one area can cause spasming in others. When I get cramping during my period I also get cramps in my anus-like a charlie horse in the rectum since everything is interconnected.
I think doctors do a disservice when they give the best case scenarios for healing. Maybe it helps to promote positive thinking which can help healing but if you don't heal that quickly (and many don't) it can add insult to injury. Tab is right-although you have had LIS you still have a fissure to heal from.
I like A&D ointment as a barrier ointment. It is in the baby aisle-regular formula not the zinc kind.
Also you might want to consider magnesium supplementation. That can help relax the muscles down there. 200 mg to start.
Hope your appt goes well and welcome to our forum!