Seeking Medical Advice: Persistent Eating Difficulties in a 9-Year-Old

Question
I know your specialty is OBGYN but I wanted another medical professionals opinion about my next step in care for my daughter.  My daughter will be 9 in Dec. and she currently weighs 45 pds and is still not able to eat.  She has complained about feeling something in her throat for a little over a month now. Over the past 3 weeks we've seen her Dr. (who is a G.P.) 4 times.  He first did nothing, next visit I suggested blood work, the results of the test were that she was a little anemic and her thyroid was off a little which he said could suggest hyperthyroidism. So he took more blood for another more specific thyroid panel and the results were within normal range. She has lost 7 pds in about 5 weeks. She is very pale and becoming tired and upset. Just this morning, I could tell she was feeling bad but she insisted on going to school only to call me by 9 am with her stomach hurting and feeling dizzy.  I realize that it is from not eating.  I began supplementing her with pediasure 2 days ago. Her main complaint is that she feels like something is in her throat. She says it doesn't hurt. She clears her throat constantly and spits. She is not hungry and besides feeling dizzy from dehydration(just guessing) she is ok.  I've asked her if it feels like she can't swallow and she says "no, it just feels like there is something in my throat when I swallow"  When her throat symptoms first began about 5 weeks ago, she vomitted for no apparent reason while at a resturant. We hadn't even ordered or eaten anything.  She only vomitted that one time but for the next few days she seem very tired and had a low grade fever for approx. 5 or 6 days. Since then she has not quite been normal.  She came to me yesterday and said "Mom, I've prayed every night for Jesus to take this out of my throat and he is just not listening, Why?"  I hate to overreact and take my daughter else where for medical treatment being her M.D. is a family friend but he deals mainly with colds and sniffles and although I don't think my daughter is terminally ill, I just want her to get well before she looses any more weight and she wants to be well.  This is a child that just a month ago weighed 51 or 52 pds and just this morning her school nurse weighed her and told me that she weighed 45 pds.  What would you do if it were your child? I have no idea what could be wrong with her. If her CBC showed no other levels off besides her iron and thyroid(slightly) what else could possibly be wrong? My daughter is a very sweet, smart girl that is and always has been seemingly happy and content.  She is becoming more sad by the day from her frustration of wanting to feel better. Any suggestions would be helpful. Thank you!

Answer
I can't give you a definitive diagnosis. I am an obstetrician. However, it appears to me that you need to have a more thorough examination and workup of your daughter. Get a thyroid sonogram, as well, to assess the thyroid gland. She should see a pediatric gastroenterologist and get cmplete X-rays of her upper GI tract to see what is causing the vomiting , the feeling of something in her throat, and the weight loss. Don't rely on the fact that the blood tests have been negative. There definitely is a problem that must be investigated.