Allergic reaction with my 2 month old? Help!

Hey everyone!

My 2 month old has been extremely gassy lately and uncomfortable because of it. He has GIANT poops all day long. At least 6 or 7. It’s been lasting for a couple days. I’m concerned because his poop has been changing in color and thickness too. (Sorry for the visual).

He is breastfed except for 1 bottle of formula in the evening before bed. I haven’t eaten anything out of the ordinary. My mom said maybe he’s having an allergic reaction to the formula I’m giving him? Or is this normal? Help!