I had an anal fissure after DS was born as well - but it didn't occur until he was about 4 months old I think - and it healed pretty quickly. My parents are both registered nurses so I spoke to my mum and she said to keep my fluids up as well as my fibre intake. I hope you heal quickly - the pain is no fun at all. I'm hoping it doesn't happen again with the next one but at least I'll know what to do next time.