22monthsold constipation

Has any mummy out there face serious constipation problem with their toddler? I feel so hopeless. If my toddler go past 2 days without pooping, she will have a really really tough time pooping, her stools get extremely hard.She cries and scream in pain, and her anus bleeds... my heart breaks when I see her like this. I have tried almost all methods - probiotics, prunes (once in awhile), barley, fruits (avoiding banana and carrot), drinking more water (she’s in preschool, so I can’t control how much she drink in school). Only solution is the doc where he gave a suppositories. Appreciate any advice!