In the unit I work in you can have fluids (clear ones - so water/ cordial are OK, fizzy drinks such as coke aren't) but no food once you have an epidural in place.
This is because once you have an epidural you are sadly self selecting into a group who are more likely to need an operative intervention and possibly a GA.
Pregnant woman are MUCH more likely to vomit during anaesthesia than the rest of the population. The classical description of aspiration of vomit in anaesthesia came from a pregnant population. In life outwith labour ward we cancel elective operations if people aren't adequately fasted as we think it poses an unacceptable risk.
Yes as a competent adult you have choices to make but as a responsible healthcare professional I also have choices to make. I have had a fair degree of verbal abuse in the past for cancelling folk who haven't stuck to the fasting rules for elective surgery but quite frankly I feel that were I to ignore the fact that they had had a full Mcdonalds breakfast 30 mins beforehand and then run into problems during their anaesthetic I think the GMC would be questioning my capabilities.
In an emergency situation (life or limb or baby threatening) we just get on with it but the risks of aspiration are higher so we use a slightly different anaesthetic technique to take account of this ie. regional anaesthesia(epidural / spinal) is first line and we only opt for GA (with rapid sequence induction) if we feel there is no other 'safe' option.
Having only this week anaesthetised someone for a section who vomited copiously I think sticking to the rules is a bloody good idea. Fortunately for her her airway was protected by a breathing tube at the time she was sick. If it had happened before all the vomit could very well have ended up in her lungs necessitating a trip to ITU. Some unfortunate individuals even die as a result of aspirating vomitus. Not the way you intend to start life as a new Mum.
I don't mean to be alarmist I just think that when you take a decision to ignore medical advice you need to know exactly what risks you are exposing yourself to.
I hope this doesn't have too much anaesthetic jargon in it.