Bubba #5 was exclusivly on EBM, and when my supply dropped and I needed to comp feed, his surgeon recommended Bellamy's Organic Formula.

It is very light on the tummy, and doesn't even smell like formula. He didn't even seem to notice the difference.
When I got my supply up, he went straight back to EBM no worries. When mixed, the Bellamy's is quite watery like BM, so he didn't go from something quite thick, back to something watery...

Good luck finding one thats suits your bubba, it can be trial and error sweets.....