My 3 year old son keeps holding his poo. We are currently in day 7 with no poo. He is screaming in pain but every time I sit him on the toilet he screams no no and refuses to. It’s so so stressful. I can’t send him to nursery because he is in so much pain. Is just don’t know what to do. Nothing I say to him works. He eats lots of fruit and veg. Has anybody got any advice?