Constipation

Just wondering if anyone has experienced something similar and has any advice. My 9 month old has always been a bit constipated but since about 7 months old she has struggled to the point she is screaming in pain. We have been to the doctors and she is on regular laxatives 3 times a day and yet she is still struggling not to the same extent but she starts shrieking and crying until I pick her up. She has had an X-ray which came back as extreme constipation. We have also tried changing her diet to avoid foods that could cause it. She does poo almost daily but they are super hard as soon as she comes off the laxatives. She still seems to struggle and constantly try to poo on the laxatives and I will change her but she hasn’t done anything. Her doctor has also confirmed she is not dehydrated and is getting enough water. I don’t want her on laxatives long term which seems to be my doctors plan. Any advice is welcomed

Thank you