Kshar sutra is a minimally invasive Ayurvedic treatment for anorectal conditions like anal fistula, Kshar sutra is a minimally invasive Ayurvedic treatment for anorectal conditions like anal fistula, hemorrhoids (piles), and pilonidal sinus. It uses a specially prepared medicated thread, which gradually cuts, drains, and heals the affected tissue. The procedure has a high success rate and a low rate of recurrence.