Shatkarma or Shatkriyas are six Yogic techniques for detoxification and cleansing of vital bodily channels or nadis of ama(toxins). It Includes the respiratory, digestive, and nervous system. Yogi Swatmarama formalized these practices even though they have been used from ancient times.
They are done before higher yogic practices so the prana or life force can flow unimpeded. They also help to balance the three bodily humours the Vata(Wind), Pitta(Bile), and Kapha(Phelgem) for bodily health by removing toxins(Ama). Typically ought to be done at the change of seasons. While most are easily accomplished but ones involving the digestive system should be done under experienced supervision/help to avoid bodily harm.