you'll be fine i went in Friday afternoon had the bypass saturday and sent home monday, feeling great and not hungry at all, still a bit tender, was staving hungry when woke up sat morning was possitively starving by lunch time but after the op not hungry at all and when i was in the room they put you out before sugery i was happy sad scared excited so many emotions running thru me i didn't know what i felt, a few hours later once i'd had it done and had woken up i was just happy, good luck and any short term risk and pain is worth it for the long term gain.. good luck and dont worry about anything just let the professionals do what they do and follow their advice after and you'll be fine
eamonn