I am doing a miralax (polyethylene glycol) bowel clean out. i started the procedure at 10am and finished at 2pm but have not had a bowel movement is this normal?

Bowel Prep.: Sometimes this happens. If results are not obtained prior to the procedure, usually either a Dulcolax suppository or a Fleet enema (sodium bisphosphate) will finish off the job

Possible: impacted stool may require manual removal or enema or or suppository. But this will be unusual in an 18 year active person. So my question is why are you doing a colon prep?