Gass drop and baby spit up

Can gas drops cause an upset stomach? I'm breastfeeding my little one and he seems to always have a tummy ache after I feed him so I tried gas drops, I gave him some last night after feeding him and it seemed to help a tiny bit so I gave him some more tonight and he got really fussy, so I walked around carrying him and after a few minutes he spit up a huge amount of milk, it was enough to soak through both of my shirts but he stopped crying after he spit up. He's sleeping now but I can feel his tummy bubbling quite a bit