@berryg - Cayenne pepper capsules tend to really clean me out so mostly just use plain old Epsom salts to keep my system regular. Dose varies between 6 and 10 grams daily depending on previous days response and I've been doing this for nearly 20 years now. It is a safe non-habit forming osmotic laxative. Some find it unpleasant to take orally but I have the "luxury" of an enteral feeding tube through which I syringe the Epsom salts dissolved in some body temperature water.
A respected Australian colorectal surgeon, Dr Michael Levitt, promotes the use of magnesium sulfate for constipation before looking at any surgical intervention, if the case seems bad enough. He has developed an encapsulated magnesium sulfate product, COLOCAP Balance as his protocol for treating constipation and as a way to avoid the chemical taste.
His plan for relieving constipation is to take it in large dose, 15 tablets over 1/2 an hour, but only once or twice a week. His book, “The Other Women's Movement” explains his thoughts on the subject. Some centres here in Australia are also now using this as a colonoscopy prep.
The idea is to promote a strong urge that can clear the bowel completely in one go so that it can relax from being empty. This can then enable the bowel to shrink back in size and become more sensitive to the natural urge to move your bowels.
http://www.michaellevitt.com.au
http://www.colocappharma.com/resources/CONSTIPATIONGUIDELINES.pdf
I haven't tried any of the following butthere are a couple of other products I've come across for constipation relief using magnesium and also incorporating an oxygenation process that is said to aid in the digestive process. They are Colosan and Homozon.
Ageless Hydro-C is another thing for constipation that I haven't seen others mention before that I have seen some positive press about.
https://www.gutsense.org/store/hydroc.html