My 14 Year Old Daughter Has Had Trouble With Constipation

My 14 year old daughter has had trouble with constipation her entire life. During her last Doctor visit a week ago she was told that she was very backed up due to the doctor feeling her abdomen. She was told she needed to start a clean out. She had been taking 2 to 3 doses of miralax daily some dulcolax and she has just liquid is coming out and the stool is trapped under her ribs or just really high up. I had her do 2 enemas and she feels like nothing is moving. What should I do next.