Hatha Yoga is the science of purification that seeks to balance the flow of prana between the lunar or ida nadi, and the solar or pingala nadis within the body. When these two nadis (energy channels) are balanced, a third channel, the shushumna nadi, is awakened to the flow of prana. In tantra this is referred to as the awakening of the kundalini. Note: Hatha does not deal with asana, pranayam or anything like that, it just deals with the purification for spiritual people. This misconception comes from
The entire science of hatha yoga is the science of purification and is a prerequisite for all raja yoga practices (meditation, asana, pranayama). There are a total of six practices within hatha yoga, we will be practicing only three this morning; neti, douti and basti. These practices provide only a glimpse into the depth of the purification practices within hatha yoga. For each practice there is a physical benefit for the body as well as a spiritual purpose.
These stored, unbalanced emotions are the main problem in life so the aim is to wash them away in preparation for meditation. This is accomplished by drinking warm salt water and triggering the gag reflex at the back of your throat to then bring the water out. The spiritual purpose of basti or cleansing of the large intestine, is to eliminate the instant karma. When we experience an emotion or desire that we are not comfortable with, suddenly we feel like eating or drinking something to escape this feeling.
These stored emotions, associated with eating are held within the large intestine and they become an obstacle in the path of life that is always pulling us down. To eliminate these obstacles a cleansing of the large intestine is required. In ayruveda the first thing they do, no matter what problem you have, is to recommend basti or an enema to first eliminate this problem in your life.