My baby is 11 month old. Earlier he used to pass urine frequently. But since past few days his frequency of passing has decreased considerably. And today he has not passed urine whole night. We keep him in diaper only at night, which we change once or twice. He is slightly straining when passing urine. But he is irritated a lot and is not eating and drinking milk properly from two days. He has no fever. What is causing him irritation. Do we need to visit doctor? Please suggest