DS2 has been exclusively bf (and expressed milk) up until this weekend. I work three nights a week and express milk for DH to give him. Over the last week I have been trying to get DS2 into a bedtime routine, so am feeding him on and off all evening and don't have a chance to express properly.
Because of this on Friday night I was at work and there was only enough milk for The first two feeds and DH had to top him up with a bottle of formula, first one he's had. Took it no problems, and slept well after and seemed fine for the day, if a bit more windy. Then last night I went to work at 8 and got a phone call from a panicked DH at 9.30, with DS2 screaming in the background, proper stopping breathing type screams, which he had been doing for an hour and shown no signs of stopping, was refusing the bottle (not a big fan at best of times) and no amount of winding, rocking etc was helping. Had to come home and try to feed him to sleep. I'm the night he fed pretty much constantly and was really farty, like fully grown man after a curry night farts, and I changed 3 dirty nappies in the night. Does this sound like a reaction to the formula? Never had this problem with DS1, but I know that DH was on soy formula as a baby. I've got a shift on Tue night and I'm dreading leaving him again 
Sorry about the essay!