A baby is not able to tell her/his caretakers that she/he is sick. What would help us to find out
(a) that the baby is sick?
(b) what is the sickness?
(a) The symptoms like fever, loose motions, vomiting and signs like behavioural changes like constant crying, irritation etc, can tell that the baby is sick.
(ii) The symptoms like vomoting, fever, loose motions indicate that the baby is suffering from diarrhoea. But to pinpoint the disease the baby should be taken to a doctor and further laboratory tests should be done in order to diagnose the disease.