i used to suffer from this and had an op on both big toes (in the community) which involved taking the nail away from both sides and leaving a bit in the middle. the op bloody hurt (well actually it was the numbing injections that REALLY hurt -3 people had to hold down my leg to prevent me kicking the man in the face).
Anyway, after that initial thing and the period immediately after when i couldn't get the dressings wet, i've had no probs since. Ingrowing toenails hurt a lot, and i remember i had to have various times off work cause i couldn't walk properly, which sounds so crappy when you are ringing in saying cant come in because of my toenail!