In Hatha Yoga, there is a great emphasis placed on cleaning one's gut and entire digestive tract from mouth to anus. This is in addition to maintaining a proper diet. The cleaning techniques are rather unique and are known as Shatkarmas - https://en.wikipedia.org/wiki/Shatkarma. In addition, Mula Bandha and Uddiyana Bandha are also relevant here - https://en.wikipedia.org/wiki/Bandha_(yoga)