Ever heard of this stuff or similar
It's crap; pseudoscience of the worst kind. Don't waste your time and especially not your money. (I can't believe what's featured on that web site. Bletcch!)
This is not to deny that constipation isn't a problem for many people post-op. Because your intake is restricted, especially immediately post-op, without extra attention to fluid intake, it's very easy to get backed up. Concentrate on fluids, and use a mild osmotic laxative like Milk of Magnesia or MiraLax if you need some occasional assistance.
/Steve