Smelly poop after upper GI/formula change?

I know poop is not supposed to smell like roses lol but Kora’s poop smells extremely sour, like rotted milk, and it’s pretty potent stuff. I can smell it even when she is swaddled up.

I was wondering if the past constipation issues or the barium from upper GI or even the formula is causing it? Her poop is normal, yellow like mustard and seedy. But the smell is just rancid

I also use Little Tummy’s Gripe Water in her bottles to help with gas issues from the formula switch. I will be using it with every feeding for 2 weeks until she is well adjusted to the formula.