Maybe 6 years ago, I had a seton sling for a recurring fistula that was too deep into the sphincter muscle to just cut and drain (although that had been tried a few times previously). Gratefully, the operation seems to have fixed the fistula and it's not returned since.
What the doctor DIDN'T tell me is that the sphincter is highly involved in keeping blood in the penis during an erection.
Once the sling was cut out, I could tell everything felt 'loose' compared to pre-op. I used to have bad gas at the time, and I was farting all the time with absolutely NO control due to what felt like a weaker 'arse' muscle.
Just by myself, I could also tell that erections were maybe only half as hard as they used to be. It was (still is) much harder to reach ejaculation, ESPECIALLY if there is lots of physical movement. I believe this is because the sphincter works like a valve to keep the blood where it should be during fun. If the valve is weak, blood leaks back into the rest of your body (understandably, it's being asked for lots of physical activity!). It deflates and then you're left with one pissed off partner

Anyway - I've read of an operation called a 'sphincteroplasty' and a few studies where this operation was able to restore/improve erectile function in those who'd have an operation to address a fistula, and I'm seeing a surgeon tomorrow to see what he knows about it. Was just curious if anyone had an experience like this or had a sphincteroplasty or, failing that, can identify with my woes and has any ideas? Kegels did bugger all!