I would have to say that treatment for constipation needs to be given for a long period of time, because if you don't do that it it will happen again, the treatment should be at least for 3 months and even upto 1 year for proper relief for constipation in addition to things like toilet training and dietary changes as suggested

Increase water intake, introduce fiber containing food items, start toilet training, more whole fruit less fruit juices  & syr duphalac for short period

Constipation !!! U can also try salads. U can give 10 to 15 ml syp lactulose or duphalac thre times a day. Please stop this syp once baby passed stool.

Pegclear 12.5ml in 50 ml frooti od for 2 weeks