K.B.
I have not been through it but have seen my dad and hubby (who has had many) go through them. Obviously neither of them were breastfeeding so I can only imagine how much more wiped out you are then they were.
After the colonoscopy they do say introduce foods slowly... well my dad did not do that (he ate a bacon cheeseburger about 30 mins after the colonoscopy, he was very hungry) and he was fine, happy & full. Both hubby & dad were fast asleep an hour after it and were sleepy till the next day, so have help with the kid(s) because it will help you recover quicker. Within 24 hours they were back to themselves but only because they took it easy for the first 24 hours after.
You are a strong women you will do great and make sure you have someone to help you at home that will make your recover time quicker. As soon as it is done find out what you can eat and eat it if you can stomach it. You will have food again soon!