not sure maybe constipation or blockage

Question
my little guinea pig seems to be trying to pass something and is in pain...vets around here are always clueless    im giving him baytrill and got him a c shot i need help i love him so much

Answer
Hi
This could be constipation or anal impaction.In either case Baytril will not do any good.
have someone hold your boy in such a way so you can access his bum.
Get some rubber gloves and a damp hanky.
GENTLY open the anus and see if there is a clump of poo. If its there you will smell it before you see it!
Wipe away any poo.
If he is constipated, get something from the chemist FOR INFANTS to treat this and give half the dosage.
Also give him loads of fresh grass.
Just as a precaution against cystitis offer him CRANBERRY JUICE ( 89P Ltr )
When he has a pee,SMELL IT. iF IT SMELLS very strong HE COULD HAVE A BLADDER INFECTION.Main thing is if he is straining,something is wrong.
I would try another vet