Ksharsutra is a Medicated seton which is made by coating the Barbour thread with 21 coatings of Kshara i.e. an herbal alkaline powder, turmeric and latex of Euphorbia nerrifolia. Ksharsutra application is a minimal invasive well established procedure in management of fistula-in-ano. Research on Ksharsutra started since 1968 and it is being used till date with high success rate. In this case report the patient was asymptomatic before 15 years but then a boil developed at perianal region which spontaneously bursted and pus discharge was seen from the boil. Patient was diagnosed with Grade 5 St. James’s university hospital classification of perianal fistulae. This was a case of high anal horse shoe fistula. In this case Fistulectomy or Fistulotomy would cause incontinence. So in this case the Ksharsutra was used but with a modification of classical technique called as IFTAK (Interception of fistulous track with application of Ksharsutra) technique. In which a window was created at 6o’ clock and intersphincteric tract was identified and in that tract Ksharsutra was placed. This technique cures such types of complex Fistula in ano with minimal tissue damage and duration of healing is also reduced.