5 month old not eating enough and slow weight gain -HELP

DS has just turned 5 months and has always been a fussy eater. Now it's a struggle to get him to feed at all. When I try to give him a bottle he clamps his lips shut and turns his head away. it doesnt matter what time it is either. First thing this morning (haddnt had a bottle since 10 the night before), total bottle refusal. Wouldnt take it at all. And this is with a clearly and loudly rumbling tummy!

Im freaking out that maybe he has a problem and thats why he isnt feeding. He has been fully ff for the last 2 months.

He has had slow weight gain (gained only 200 grams in the last month) so this is making the situation worse.

Sorry for rambling. Anyone had any ideas?

I don't know about long term solutions, but i would be worried about trying to give him some formula right now. Have you tried using a teaspoon and giving him formula that way? You can also try cup feeding- a shot glass or small medicine cup works well for little bubs.

here is some info on cup feeding (its about half way down the page) Australian Breastfeeding Association - Cup-feeding

Did you have difficulty breastfeeding? If he has a tonguetie or similar that made breastfeeding difficult it might also be making bottlefeeding uncomfortable for him. Just an idea. Do you have a mchn you like that you can talk to?

Sounds like he may be teething? My kids did this when their gums were hurting. I rubbed some SM33 on their gums, and then they would feed properly.