My daughter who is 8 years old with down syndrome has dealt with constipation for nearly 5 years. We used apple juice and suppositories for awhile and the last 2 years she has had bladder infection symptoms. Took her to urologist and he recommended putting her on miralax. Started miralax and it got her going at least 3 times a week rather than once. She started vomiting/diarrhea so we thought she had flu bug. I stopped miralax. It continued off and on for next 2 weeks. Went to pediatrician. They thought it was not viral and sent us to gastrologist. He did xray and she was not constipated and did blood work to rule out celiac. Few days later she was vomiting and diarrhea again. Still not taking miralax. Got blood work back yesterday and no celiac. Told us to give her a colon cleanse with miralax and chocolate exlax. Woke up this morning and it did produce a BM and she s vomiting. Should it cause her to vomit? Is this IBS? Could the miralax be causing the vomiting/diarrhea?