An infant is crying excessively even after being given good fed. He is passing a large quantity of urine and repeatedly getting dehydrated. Urine examination shows no proteinuria and a specific gravity of 1004. The most likely diagnosis is –: (A) Diabetes mellitus, (B) Diabetes insipidus, (C) Congenital nephrotic syndrome, (D) Protein losing enteropathy
Answer is B. This child has low urinary specific gravity.
Amongst the given options only DI causes low urinary specific gravity.