Hi and thanks for the query,
Infants of this age can drink about 40 to 60 ml per feed. This is not a rule and depends on the individual baby.If the child is gaining weight normally, passing urine and stool normally, then you need not worry. Feeds change with illness also.Please do not give any water will sugar, gripe water or other such things as they will decrease the amount of milk taken by child, If you are giving formula feed, stool may be green if the feed contains iron. You need to worry about green stool
if it is associated with mucus, foul smelling or blood stained.
Hope you are reassured.