Prep for anal

Hey , I will be bottoming tonight for a guy and I haven't really had much sex before. I haven't eaten today but yesterday evening I ate a LOT of food with my friend.( Pizza/ Desert/ Crisps / chocolate 😭) basically munchie food. I was wondering what I should do today , I guess go to the toilet then douche before going to his, can I eat from now until tonight ? I will be at his in about 6 hours