Bladder is present close by the urethra and its color is red. The activity of cleansing the bladder is called vastikaram. According to yogasara book, the practice of vastikarma should be done after subjugating the apaan vayu by taking tablet which is made by mixing old jiggery, trifala and the juice of lead-wort bark together. This activity is done by two techniques as- pawanvasti and jalvasti.
Abandoning the air in mayura asana after stretching apaan vaayu up through the anus with the help of a pipe is called pawanvasti. After doing pawanvasti, jalavasti becomes easy. First, fill water in a tub for jalavasti. Fill As much water in the tub that the navel region may sink into the tub properly. After that, take a six inches long pipe of bamboo and it should be thin on one side and thick on the second side. Insert this pipe into the anus till four inches and sit in utkata asana.
viz. Put both the tiptoes down and touch heels with the hips and keep it raise. Now shrink anus and stretch inwards. The water will fill in the intestines by it. Thereafter, exclude this internal water from the anus by noulikarama. Thus, the stool stuck inside is brought out by filling water in the intestines. In this way, the bladder becomes pure and clean by it.
This activity is very difficult, so do it carefully and in the supervision of any yoga guru.