Through the shatkarmas, harmonization of ida and pingala, the two main flows of prana, is established, resulting in physical and mental purity and balance. The shatkarmas also balance vata, wind, pitta, bile, and kapha, mucus, the three disorders created in the body. According to ayurveda and hatha yoga, any imbalance in these three disorders gives rise to disease. The shatkarmas are also utilized before pranayama and other higher practices of yoga so that the body becomes free from disease and does not create any obstacles on the spiritual path.
These powerful practices should never be undertaken just by reading about them in a book or by learning from inexperienced people. According to the tradition, a person has the right to teach others only after being instructed by the guru. It is essential that these instructions are given personally, including the knowledge of when and how the practices are to be done, according to the needs of the individual. Gheranda Samhita (Chapter 1, Verse 12):
Dhautirvastistathaa netih laulikee traatakam tathaa;
Kapaalabhaatishchaitaani shatkarmaani samaacharet.
Performing the shatkarmas: dhauti, basti, neti, lauliki, trataka and kapalbhati, is essential.
In this verse, the six types of cleansing practices are listed: 1. dhauti, 2. basti, 3. neti, 4. lauliki (also called nauli), 5. trataka and 6. kapalbhati. The shatkarmas purify the body. Their purpose, however, is not only physical purification, but inner purification as well. When the body is purified, internal disorders are removed and good health is achieved. Without such purification the body will not be ready for the higher practices of yoga.
After purification a human being lives longer on this earth. In the Upanishads and Vedas it states in a number of places that human beings live for a hundred years, jeevema sharadam shatam. This is not only the thinking of the Vedas, Upanishads or ancient philosophies, it is the truth. If a human being remains healthy and free from disease, living for a hundred years or more is natural. Accurate genetic copying of the cells can continue for that length of time if the programming is not disrupted by impurities or imbalances.