"After the federal government introduced Bill C-56 in late June that would restrict how long inmates can be placed in solitary confinement..."

That statement is incorrect. Bill C-56 does NOT restrict how long a prisoner may be kept in solitary confinement. This includes younger offenders and prisoners with mental health issues. Bill C-56 simply requires that the warden who sends the prisoner to solitary confinement shall file a report on the matter after 15 days. After that, there's no limit to the amount of time a prisoner may be kept in isolation. 

You can see the facts for yourself at the following link:

http://www.parl.ca/DocumentViewer/en/42-1/bill/C-56/first-reading