Hi well come to HCM.
It could be due to gastritis
. Consult your doctor and let him asses for dehydrtion
Its already one week child is suffering, and as such regurgitation ia quite painful to
the pt.So better consult your doctor since baby is having regurgitation it will be difficult
to retain oral medication for him. In that case some injection like ondencetron or
metclopamide may be required. Thanks