Creations- my LOs BM are all "well formed and self contained", but it's like it burns her bottom as it comes out. I change her right after she has one, but still got the rash. It's almost gone now. We went without solids yesterday, and today I reintroduced avocado, pears, and squash as I'm almost positive it's none of those. We'll go with these again tomorrow to make sure, and then I think I'll start introducing new solids and try bananas and rice cereal in a bit. My doctor told me today that it takes time for babies to get used to certain foods.
But she was also constipated, and rice cereal can be constipating, so I'm betting that it was rice cereal that caused it. Not sure why she'd get a rash from that though. Good luck with your LO. Wow, 300 food types is not fun problem solve around!