My coccyx was damaged in labour. I don't know what the damage is as the doctors (I've seen quite a few) won't x-ray it as they say that even if it is broken, there is nothing they can do about it except let time heal it. This isn't what you really need to hear when you're trying to look after a new baby. Initially when I sat to feed him my coccyx would crack (one doctor said this was a good thing as it was moving back into place, but I've come to realise it wasn't a good thing) and I could move it around manually. The pain was just awful. First of all the midwife told me 'Of course it hurts, you've just had a baby', so I presumed this was normal and it would go away. Eventually I realised it wasn't normal and have been to see various doctors, but they weren't very helpful. One even told me that the pain was psychological and that if I stopped worrying it would go away. I've been to physio and an osteopath several times but I'm sure it makes it worse, so I've stopped that. The strongest painkiller you can have whilst breast-feeding is codeine, but this is a bizarre, trippy drug and leaves you in no fit state to look after a baby. It also says 'may cause drowsiness' on the packet, which is a bit of a joke when you've had months of sleepless nights.
However, eventually I spoke to a wonderfully helpful woman who specialises in pregnancy and post-natal care (of mothers rather than the baby) who suggested the following. I'd like to share it with anyone who is experiencing the same, as I know it would have spared me a lot of pain if I'd have had this advice sooner.
I have been avoiding sitting at all costs for a month now and although I'm still in a bit of pain, it is nothing like it was and my coccyx hasn't 'cracked' during that time. I feel a bit daft sometimes standing up (in the doctor's waiting room, on trains, etc.) but the benefits have been well worth it. If you are suffering from this, you have my sympathy - it is really awful.