My baby keeps bursting out crying. What could be the reason?

Likely trapped wind . Are you thoroughly burping her? Infacol can make things much worse if not used correctly.

Is it equally worse after breast or formula? x

Go with your instinct and keep getting her checked if you think its something more than her stomach.

Additionally my baby cried like this since day 3 for 2 months and i was going insane. Babies are adjusting to the new world and environment outside of the womb, everything is new and uncomfortable for them, and their intestines are really small and fragile so everything literally hurts. Just be patient, keep your baby upright after feeds, feed her at an angle and with bottle try paced feeding too.

Additionally see if the formula you are using suits her. Sometimes formula is heavy too for the baby and they don’t take it really well.

I had this with mine, who’s now 6 weeks old.
I started pumping as exclusively breastfeeding was exhausting and I’ve found that she probably wasn’t latching properly, nor getting enough. Which was causing her to take more air in.
Also, when they cry, they gulp more air, which adds to it.
Ive found that bicycle legs work wonders for relieving trapped wind

My baby girl did this too, from a similar age until she was about 11 weeks old, also mostly breastfed but had 1 bottle of formula a day. I did find that infacol made it worse for her as she wasn’t going for a number 2 as often & I think it blocked her up. The only thing I found that really helped her was a warm bath🥹 I’m sorry your baby girl is going through similar, I know how hard it is seeing them like that!!

One thing I’ll say is infacol made my baby worse when he was little… he was fussy before it we tried it and it’s made him 10x more fussy and gassy so maybe look into that too..

I remember this like it was yesterday, for a good couple of weeks my son would take days to poo, he would be crying, scrunching up.. I went to the doctors back and forth loads and one doctor even said to me ‘I can tell he’s your first because you’re worrying about everything, you just need some sleep’.. safe to say I kicked off🤣
I know formula fed babies don’t poo as much as breastfed, but in the end I just changed his milk and within a couple of days he was pooing everyday.. we changed from Aptamil to Hipp Organic as it has prebiotics in it that help with digestion x