my baby has taking feed properly means 20 25 min but after 20 days it gradually low means taking 5 minutes and gets weak and crying after we haves antibiotics it starts to get feed again 20 min it happens always after 20 days 20 days frequently what we have to do we dnt get permanent solution please tell me we are so bothering about this doctor also not telling what is the issue simply they are telling infection infection but blood urine tests are all normal and this time same happens now doctor gave me nexpro junior we gave 5 days she will taking feed but after 2 days again she stops and comes to low 5 min please tell me what causes