Shatkarma yoga is the combined name for six techniques of cleansing the body. Karma is an act. Shat or Sat means six. In Hatha Yoga, there are six procedures or techniques for cleansing different body parts. They are called Shatkarma or Shatkriyas. They are nauli, basti, trataka, kapalabhati, neti and dhouti. They are also called suddhi kriya (procedures of cleaning).
It is very important for a student of Yoga to keep himself physically and mentally fit. Any ailment means an immediate impediment in the practice of Yoga. For example, constipation in the intestines creates obstruction in the practice of pranayama. Any obstruction or gap in Yoga practice has its undesirable effects. Therefore, a student of Yoga is always required to guard against an impending possibility of ailment or disorder and take steps to avoid it before it strikes and disturbs the continuity or efficiency of Yoga practice. Hence, whenever a student finds any impurities accumulating in the body, he is expected to take steps to remove them by the cleansing procedures. These cleansing techniques are practiced only when there is need, but nauli and kapalabhati may be practiced every day.
When a student learns pranayama (breath-control), he may be required to follow the cleaning procedures first. But as mentioned in Hathayogapradipika (II.37), pranayama itself is the best purifying technique for all the organs and functions of the body, and so for one who practices pranayama regularly, it is not necessary to do any other cleansing act. But for others, the six cleansing procedures are certainly quite useful for removing impurities and promoting health. Svatmarama has himself recommended (Hathayogapradipika II.21) that if there are impurities in the nose or throat before starting pranayama, one should remove them by the satkarmas, and then only the practice of pranayama should begin.
Nauli is said to be the foremost and the most important among the kriyas (Hathakriyamauli). Obese people who carry a lot of fat on their bellies cannot do nauli, because it is not possible for them to isolate and move the front abdominal muscles right and left. For them, agnisara is a very useful substitute for nauli. It involves movement of the abdominal wall forward and backward and also from side to side. This can be done conveniently, even by the obese and the elderly.
Basti cannot be practiced without doing nauli, because, in basti, water is sucked through the anus by creating a vacuum inside the abdominal cavity by doing nauli. So, those hwo cannot do nauli have to take recourse to enema by using a pot and tube, instead of basti, though enema is far less effective than basti.
Trataka is a cleansing act for the eyes. It is usually practiced with open eyes, fixing one’s gaze on any object without blinking the eyelids. Or it may be done keeping the eyes closed, which is a less strenuous way to do it. Moving the eyeballs in clockwise ad anti-clockwise directions and pressing the eyes slightly with the fingers or with the palms provides a good exercise to the eyes. It is useful in removing congestion and promoting blood circulation.
Kapalabhati is wrongly called bhastrika by many. Actually, bhastrika is a type of pranayama and as such, it includes four stages, such as
- Rapid and incessant inhalations and exhalations
- Puraka (inhalation)
- Kumbhaka (holding of breath)
- Recaka (exhalation)
Each round of bhastrika pranayama, would, necessarily, include all these four stages. The first stage in those four is kapalabhati. The confusion between the two words arises from the fact that in kapalabhati, the abdominal wall moves back and forth like the bellows, which are called bhastra or bhastrika in Sanskrit.
Kalpalbhati differs from both normal breathing and from pranayama. In normal breathing, exhalation is a passive act which comes about due to the elastic recoil of the lungs. But in kapalabhati, inhalation is a passive act and not exhalation. In pranayama, both these acts are prolonged and deep, whereas in kapalabhati they are very short and shallow. The lung ventilation per minute is enormously increased in kapalabhati.
Neti involves cleansing of the nasal passage and the pharynx. This is achieved by gently rubbing with a smooth thread or rubber catheter or by pouring water through the nose. The last one is called usahpana, as it consists of drinking water early in the morning (through the nose). Both the nostrils are used simultaneously for this. In winter, lukewarm water may be used. It is very useful practice for cleaning the sinuses and for eye care.
Dhouti can be done in three ways – by drinking three or four glasses of water and vomiting, by using a tube to draw out water from the mouth, by swallowing a long strip of cloth and then pulling it out. In Gheranda Samhita (I.14), four varieties of dhouti are mentioned, namely, vatasara, varisara, vahnisara and bhaiskrita dhouti.
Source – Encyclopedia of Hinduism Volume IX page 315-317 - IHRF