Suggest Remedy For Severe Constipation In A Toddler

MY grandson is almost 3 he told his mom he wanted to start going potty on the toilet and has done VERY well no accidents at all the only exception is that he will not poop. He won't go on the toilet or in a diaper it has been 8 days and I am worried it is going to make him sick. How can we get him to go?