Hi there. I so understand what you are going through. How old is your little ds?
I have/had 2 dc who are ftt. ( failure to thrive) My ds who is my 2nd child was born at 9.5lbs but stopped gaining weight at 4 months till 16 months. He refused to eat anything except breadsticks and custard. He also had severe silent reflux and then developed a real phobia of food and didnt eat. We had feeding clinics, test, assesments etc it seemed every week. he never seemed hungry and the classic "leave him, he will feed when he wants something" ended up with us in hospital with him on a drip due to dehydration and one consultant mad at another!! He has plenty of health problems (strangely nothing that is do do with eating/ digesting etc)
When he was 13 months i had dd2 and he seemed to change over a 2 month period. He started eating things and being more relaxed about food and life changed so much. I remember i bearly left the house with him before then as it was embarressing if we were out when trying to get him to eat. People used to comment etc. Then it all changed slowly, i declined going to all the clinics (as we had established him not eating was NOT a medical reason) and i became more busy with dd2 i chilled alot more. He said he didnt want to eat and i said ok. Now i have a 2.5 year old who will try anything. he still has a small appetite but meals are no big deal. He sits , eats what he wants and i clear away. hee also in the last 3-4 months has started to ask for food around our meal times, so to me showing that he now has the ability to feel hungry. He is still small for his age, in 12-18 months clothes. But is a healthy weight for his height and gaining weight steadily now.
I know exactly how you feel though as i am now going through similar with dd2. She was born at 8lbs and now at 16 months weighs 17lbs. She is just starting to go into 6-9 month clothes, she is so tiny and has no fat on her. I hold her hands as she walks and feel i could snap her little wrists.
She never took to milk, not breast or presciption formula. If she ever took 3.5 oz we phoned the grandparents to celebrate! lol.
Strangely she was a very content baby till we started weaning. I didnt start till 6.5 months, on consultants advice. She is now very fussy and clingy and tired etc all the time. She adores solids. She always wants to try stuff and eats the same as dd1 and ds. She prefers blw and i am happy to go with that. However, she doesnt have a huge size meal as expected as she has a tiny tummy, but she does not gain weight and very regularly loses it. She does suffer from digestive problems and is on medication as she gets severe constipation (bad enough to infect her) and then runny tummy! Thankfully though meal times are not an issue with her so eating out and about is fine.
We are just starting the route of investigations into her very slow weight gain as they think it is more than just her being "diddy".
Im so sorry this is so long. If you want to chat i would be happy to email etc. Would love to hear more about your ds. How old is he? what have they said so far etc.
Its hard when it isnt your first isnt it as you feel that you should know what to do and what is going wrong!