11 week old crying after every feed

[Lockdownbaby2021]

My 11 week old this last week is screaming after every feed!
badkground story, been on kendamil since birth, had a rough patch around 3 weeks, trialled a CMPA prescribed milk but made him
worse so went back to kendamil. We’ve had tongue tie cut + osteopath sessions and my boy was so content even when feeding.
then at 8 weeks old he was in hospital on antibiotics for urine infection. We gave probiotics during an after the course. However since being on antibiotics he’s screaming every time he’s finished his milk. He’s on 5oz every 3 hours. I burp halfway through, hold upright and pace feed. I thought at the start he may still be hungry so I tried making up 2 more ounces and he’d drain it and be even more uncomfortable.
i refuse to be on gaviscon etc as my first had that and he was so constipated! Could the antibiotics have messed his stomach up permanently?? Other than this he’s very smiley after waking up, but then he will feed and the cycle will continue!

Which milk did you try. If it was an extensively hydrolysed one it will have still had dairy in and the reaction would suggest that an amino acid one is necessary
It could be reflux still. They might benefit from omperazole.
My daughter screamed and for her it was a combination of reflux and allergies. She improved by removing the allergies. Having high dose omperazole, gaviscon and lactulose for the constipation. She was on and off the gaviscon for 10 weeks before we were offered the lactulose. It helped but caused her poos to go to rabbit droppings that she struggled to pass. Ultimately she needed domperidone too and after a few months didn't need the lactulose. She's 3 and still on this combination

I might be stating the obvious but you say you burp half way through ,do you burp after feeding too?

@Superscientist yes it was partially hydrolysed. Pepti 1. He was worse on this than kendmail though and he’s so happy otherwise! My first had CMPA and he was so miserable but the Pepti worked wonders! So that’s why I’m thinking it’s not CMPA and something to do with antibiotics.
@MrsPelligrinoPetrichor yes I burp after too and he lets out some good ones!

Illness and antibiotics can cause secondary food allergies/intolerance which are usually temporary. It might be worth trying a tin of lactose free formula

@Superscientist funny you say that. I saw somewhere else that antibiotics can cause a temporary lactose intolerance. I wonder if a colactase drops or lactose free formula like you suggested may help! I’m seeing the dr tomorrow for our mum and baby check so will ask then too! I just wondered if anyone else found that antibiotics caused the same effect on anyone else’s babies! Thank you for for your help 🥰

My friend did a trial of df whilst breastfeeding her daughter after a course of antibiotics for her upset babies tum. She had loose stools and colic probably a touch of reflux too. I think she trial df for about 6 weeks with minimal changes, she went back on dairy with no worsening of symptoms and gradual everything improved in time. It's always hard to say what the cause and effect was but she did wonder about the antibiotics