Constipated 4 yo - advice needed please

[Baysmum]

Just wondered if anyone could advise me about my son's awful constipation? he has always had problems since birth and saw a consultatnt for a while as I was worried that he would be starting school in pull-ups . The consultant put him on Movicol and he gradulaay reduced until the problem seemed to be in the past - though he still often goes about 4 or 5 days between poohs. Anyway, it has now bww approx 3 weeks since he last poohed and he has impacted bowels.He has been on s sachets of Movicol for almost the last week and a half, we took him to Aand E friday night with stomach pains and they gave us glycerol suppositories - both of which have done nothing much! He was at the hospital on Monday where they put us on a high dose of Movicol but if he doesnt pooh by Friday I think they will give him an enema - possibly under sedation as he gets very distressed!
He drinks loads, has a healthy diet and no physical problem that should cause this. I'm at my wits end - any ideas?

What do you mean by healthy diet?

My dd at age 4 ate Crunchy Bran for breakfast and usually ate all her veg but left whatever the protein of the meal was. She produced 4 pottyfuls of poo a day. She drank very little milk if any after weaning at 12 months.

I am not a medical professional but is he maybe afraid to poo after all the trouble he has had? He would then hold it in for as long as possible which would make him constipated if he cannot relax.

I have heard of other people having this problem and this being one of the reasons, although apparently it can be just one of those things.

good luck!