The problem with waste accumulation is not solely in the accumulation itself. The problem lies in the fact that the waste is partially absorbed, pollutes the various systems of the body and causes other cumulative damages. Therefore, care should be taken to move the bowels regularly so that the waste from the body is removed at least once a day. This is so significant that the Rambam wrote the following in Sefer Hamada:
A person should always try to have loose movements throughout his life, tending slightly towards diarrhea. This is a cardinal principle in medicine: Whenever one suffers from constipation or has difficulty moving his bowels, serious diseases will beset him.
It should be noted that constipation does not only have adverse effects on a person’s physical health, but it also affects his mood. Oftentimes, a person may find that he is restless or that he reacts to various situations with anger. He does not realize that the internal pressure in his body, due to constipation, is the main cause for his restlessness. Once he relieves himself, it will make things easier for him and everyone around him.
In order to help the intestines function optimally, it is important to drink a lot. Drinking a few cups of water, grapefruit juice or other tart juices often helps the intestines. Fiber-rich foods such as fruits and vegetables, bran and whole wheat bread activate the intestines causing them to expel the fiber, as it cannot be digested. Fiber has two functions; it absorbs toxic and harmful waste and expels it.
However, eating bran requires much fluid intake. Without a sufficient amount of fluid, it will add bulk to the waste product in the intestines and make it harder to expel. Prunes and prune juice also help move the bowels. In special cases, medication can be used for this purpose. However, it should be used sparingly. But even when it is necessary, natural remedies should still be the preferred choice over synthetic medications.
Notes and Sources
 Rambam Hilchot De’ot 4:13
Adapted from “The Keys to Life” by Rabbi Zamir Cohen