My youngest NEVER took more than 10- 12 oz in 24 hours.
When she was 8 weeks, I took her to a paediatrician which thankfully, my health insurance covered so I didn’t have to wait or mess around with HVs or GPs
No reflux. No stomach issues. No tongue tie. No allergies.
We tried different bottles and teats - not milk though as she was on kendamil which is excellent.
We resorted to feeding her when she was just falling asleep - that was the only way to feed her at all in the end.
She did somehow gain weight. She was born on 3rd centile and went to 50th and stayed there - Christ knows how.
Anyway, with no answers as to why she just refused to take milk, the consultant told me just to start her on solid food at 15 weeks (which I didn’t find shocking, I have a son in his 20s and 16 weeks was standard back then). Obviously not recommending that to you - just sharing what we were advised for our situation.
She liked food. But wouldn’t eat anything with milk in. However, she loved plain Greek yogurt.
I was so worried about her for so long.
She’s five now, still an awkward bugger who won’t do anything you want her to do, and guess what, her favourite snack since she was 2 is weetabix with a ton of milk, and she asks for glasses of milk everyday.
Anyway, get him checked out, especially if you are worried about his weight gain.
ERA - just seen he’s 14lb at 5 months. Get him seen urgently. Mine was different as she somehow grew and gained weight ok.