They don't give enemas as a standard procedure any more but you can ask for one if you want or if you prefer I saw an enema kit in a chemist last week so maybe you can DIY.

I did a poo while I was pushing - they say that you don't mind and on one level I didn't but on another level I did IYKWIM.

Its not likely that you will make a huge mess and the midwives are used to cleaning it up.

On your birth plan you can ask DH or your midwives to remind you to go to the loo reguarly and to try to empty your bowels at the beginning of the second stage of labour.