My guinea pig has diarrhea (again!!)?

i think its too much gr, well when i put my guinea pig outside he got really runny poop after eating the gr, it was ok the next few times he ate the gr again, and then a bit later he got diarrhea again but like your guinea pigs, it ped within a few hours, so id say its too much gr or greens. btw, my other guinea pig didnt get diarea tho, so i think some guinea pigs are just a bit more sensitive than others.