[QUOTE=namelesswonder;961345]I don't recommend senna. The reason why it works is that it[I] irritates the lining of the bowel[/I]. That's nearly as bad as loading up on fiber.[/QUOTE]
Fiber is not bad, nor is it constipating if taken properly with water. There are different forms of fiber though. There are soluble and insoluble fibers. And in the insoluble fibers you have hard and soft fibers. I don't like the hard fibers like wheat bran or psyllium. But I do like the soft fibers like rice bran and oat bran, which are also very nutritious. I also like the mucilages since they not only help things along, but they also act as a stool softener and soothe and protect the mucus membranes. They are not irritants like the hard fibers.
Fibers serve other purposes as well. For example, fibers feed the intestinal flora. This not only helps keep us regular, but the flora also produce beneficial acids, peroxides and bactercides that help protect us from pathogens. The insoluble fibers are also our primary source of silica, which is essential for healthy bones, cartilage, nails, skin, teeth, hair, tendons, ligaments, blood vessel walls, etc.
[QUOTE=namelesswonder;961345] Magnesium affects your muscle control. It causes the muscles of your intestines to spasm and expel the waste.[/QUOTE]
Magnesium does not cause muscle spasms. Just the opposite. Magnesium relaxes smooth muscle by blocking the action of calcium, which causes muscles to contract. This is why magnesium is also used to dilate the bronchioles in asthmatics, lower blood pressure, stop nocturnal muscle cramping and restless leg syndrome, etc.
There are different forms of magnesium though. The worst is magnesium oxide, which in water forms magnesium hydroxide. The hydroxide is caustic and burns the intestinal wall causing an influx of water and stimulating peristalsis due to the irritation. This is why Milk of Magnesia is used as a laxative. Acidified forms of magnesium though do not do this and much better absorbed.
Other forms of magnesium work by attracting water in to the intestines.
But neither magnesium, nor vitamin C are stool softeners, which is what the original poster was specifically looking for. A big difference between laxatives such as high dose vitamin C and stool softeners like slippery elm is that laxatives can cause diarrhea as where stool softeners do not.
[QUOTE=namelesswonder;961345]Vitamin C will soften things up and get you going. I can't remember the mechanism, but since you can take such high doses and there's no known toxicity level for human, I recommend above anything else.[/QUOTE]
Vitamin C works in the same manner as acidified forms of magnesium. These are osmotic laxatives that draw water in to the intestines.
As for the claim there is no known toxicity level that is not true. There is no known lethal level, but that is not the same as toxicity. Diarrhea for example can be considered a toxic effect since it can cause electrolyte imbalances. Excess vitamin C can also cause kidney stones in people with pre-existing kidney disease. Vitamin C also functions as a pro-oxidant instead of an anti-oxidant in higher doses to name a few.
Also keep in mind that the synthetic ascorbic acid and ascorbates commonly sold on the market are extremely unstable and rapidly break down in to oxalic acid, which is a tissue irritant and binds with certain nutrients like calcium preventing their utilization by the body.
But in the OP's case, constipation caused by Vicodin will not be cured by fiber. The OP was looking for a way to combat constipation caused by a pain killer and Vitamin C is only a laxative if you take too much. Otherwise, it just softens. That's why you build the dosage up.