Milk of Magnesia - best for constipation and everything that comes out with it.
This is probably the simplest. There's a bit of it in those Renew Life products as well.
The renew life also comes with a liver cleanse formula.
It's accompanied by a very gentle laxative.
When I was younger, my Mom would give us a purge every month with Senna tea and a block of Ex Lax.
We'd just have a very liquid based soup for the rest of the day.
She would often consume Bekunis herbal tea.
You don't want to use these products too often such that it upsets your natural balance though.
Even too much fibre can be harmful.
Nothing beats eating as clean and healthy and as balanced as possible all the time though.