Cows milk protein allergy - poo in photo!

Please don’t look at the photo if you’re eating! My baby has had two poo’s with blood in. Went to the dr and they said he has a cows milk protein allergy and needs to go on special formula. Currently he’s on kendamil goats milk because we did feel he didn’t get on wit normal formula. He’d moan a lot after eating and draw his legs up. He seems to be doing ok on goats milk. He also has reflux and is on gaviscon and has mild cradle cap. I’m wondering if it really is cmpa as he’s just turned four months. Surely we’d know by now? He only started getting blood in his stool last week and he was on cows milk formula for almost three months. Anyone else had a similar looking nappy and it turned out to be something else or even cmpa?