don't worry, i've been through the worry... about everything
when did he have his ga?
aslong as he is eating, drinking, pooping then he sounds ok and may just be recovering from it all.
has he done anymore dodgy poops? could they just be caecotrophs? or did it seem very runny?
keep an eye on him and see if he does anymore. i know my two have done some excess caecs after a ga, or when stressed. usually only a few though and that was aswell as normal poops.
sometimes medications and stress can affect the gut slightly and cause them. sometimes they leave them for various reasons, but seen as he has just been through a ga, i would say that is why, but any change in his normal behaviour then i would ring the vets for advice.