The bottom line/truth is this:
Cascara sagrada, henna, turkey rhubarb and ALL herbs that stimulate the action/peristalsis/squeezing of the colon, do so by irritating the colon, and that's why the colon squeezes...to try to get them OUT because they're an irritant!
When there is NO build-up or mucoid plaque in the colon, it's bile from the liver that triggers the sqeezing action of the colon. But of course, when there is buildup, the bile can't get to the lining of the colon in order to cause the colon to squeeze.
These herbs DO NOT break down, disturb, or function in a way to destroy/soften/or eliminate mucoid plaque, but when used with fiber (flax, psyllium, pectin, etc), the combination of the two will soften/break down the buildup and squeeze it on out...bringing your body back into a natural state of health.
There is no question, that having regular bowel movements daily is better than not having regular bowel movements. And to me, there is no question that an herbal "squeezer" is better than a chemical 'cleaner' (because at least, the colon IS getting some exercise!). When there's an incurable/major disease involved, the usage of these products is fantastic for healing and restoring health. However, there is also no question in my mind that to use an herb to do something that the body SHOULD be doing naturally and on it's own...means that one is using the herb in exactly the same way we use a pharmaceutical drug...to cover up the body's symptoms and problem by using a drug or herb, rather than "hearing" the body's cry for help, and eliminating or healing the actual problem.
If one's diet is correct; they exercise enough; drink plenty of fluids; have a liver that is functioning well and producing the bile that is needed by the body...AND a person has gone through a complete and thorough colon cleanse to rid the body of mucoid plaque (with a few maintenance cleanses along the way)...it is unnecessary and unnatural to take an herbal "pharmaceutical" on a daily basis for the rest of one's life in order to attain regular bowel movements.
These herbs have a place in cleansing and healing the body. But they ARE an irritant to the bowel, and that's how/why they work. Unless a person has severe nerve/intestinal/body damage, or cannot (or will not!) change their lifestyle and do what it takes to achieve truly natural digestive/colon health, to rely upon them daily to do something that their body should be doing naturally...goes against nature and is not natural (no matter how natural the herb may be).
Take it daily if you wish; watch out for the possible long-term side-effects; but please don't fool yourself into believing that it's a "cure"...it's simply another concoction that covers up the symptom of what is wrong.
P.S. And another thing to consider (for what it's worth): I've studied the works of Christopher, Schulze, Gerson, Kelley, Batmanghelidj, and many other time-honored natural healers. The ONLY ones that recommend these types of herbs for continued, daily use (in the absence of a life-threatening disease or specific need) are those that sell them.