My horsefield Flash was sick

[JSudsy]

hi guys my 1 year old horsefield tortoise flash was sick after eating his lunch.
it was only the once he sort of made a squeak before being sick.
He was only eating the same as he's had before and had no reaction to it.
I have bathed him and he drank plenty of water whilst in there I continued this twice a day for a few days to keep him hydrated.
He seems his normal self now but I was just wondering what could have caused this.
Thanks in advance
J