We go to Dr Agnes Tay, Alpha Baby, near Jurong East MRT. Tel: 67958660. She's friendly and don't have to wait too long. Usually just make appointment, go on time and you'll be next to go in.
But actually, constipation don't have to go to doctor. Just more fibre fruits, like papaya, banana, and vegetables in diet, drink more water too, then should be able to go. If really can't, can try prune juice, or better still, mix prunes (cut to very fine pieces) with his/her oatmeal. With more fluid and fibre in his/her diet, can sure go regularly.
Try out all these natural ways before medicinal help ya.
Cheers.