### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
My baby niece is now 4 weeks old. since day 10 she has been hospitalised twice. First due to rapid weight loss and poor feeding, which was attributed to a viral infection, she was discharged and 2 days later re-admitted due to poor feeding. The main problem since approx a week old seems to be that she cannot take more than 3 ounces of feed without vomiting or falling asleep. Whilst in hospital she has been fed through a tube and whilst they feed little and often this worked ok, however each time they try to up the volume and feed at longer intervals the same problem re-occurs. The doctors have checked bloods, saliva, water sample etc and have now put her back on 2 hourly tube feeds to ensure she is getting sufficient feed. My sister is convinced that there is something internal that is preventing the baby from taking more than 3 ounces, but the hospital seem reluctant to investigate. They are treating the baby for reflux and have 2 days ago changed her to a non-cows milk feed in case it is lactose intolerance, however the same problems still seem to be occurring - vomiting and sleepiness. The doctors asked if they could feed the baby for 24 hrs (bottle) so they could observe for themselves, and I assume to see if there was any issues with mums and dads techniques, but the sames problems occurred, hence she is now back on the 2 hourly tube feed. She is not putting weight on, however is not losing weight either. Any suggestions as to what could be preventing an otherwise healthy baby from properly feeding?

### output:

Hello, We need to know the birth weight in this child and the present weight, followed by the number of times the baby passes urine, stools.  There might be an inborn error of metabolism which needs further investigation.  Plus feeding technique needs to be assessed. Monitor the weight gain daily. And please get me back with positive weight gain. Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor. 