Your patient has not responded to the standard Miralax protocol. He/she now suffers from Functional Fecal Retention and an inability to control overly loose stool. The former solution has now become the problem.
This requires an entirely different approach which is set forth in The Clean Kid Manual 6 (6th Revision). Suppositories and enemas are used on a daily basis to establish positive control to end soiling and empty out the colon for a 24 hour period. Contrary to current pediatric belief this is not traumatic because child and parental control is much more quickly achieved leading to substantial psychological relief. The over retention and drying out of stool is lessened. This gives the colon the opportunity to recover and the child learns to reconnect his urge signals and voiding responses through Pavlovian Classical Conditioning.
A summary of my protocol is set forth in an invited paper I wrote for The International Foundation of Functional Gastrointestinal Disorders dominated by Gastroenterologists. You can download it at (http://www.encopresis.com/exam-request/).
Robert W. Collins, PhD, PC