This what happens during the procedure. 

LIFT (ligation of inter sphincteric fistula tract) procedure, is based on secure closure of the internal opening and removal of infected cryptoglandular tissue through the intersphincteric approach. Essential steps of the procedure include, incision at the intersphincteric groove, identification of the intersphincteric tract, ligation of intersphincteric tract close to the internal opening and removal of intersphincteric tract, scraping out all granulation tissue in the rest of the fistulous tract, and suturing of the defect at the external sphincter muscle.

Not all surgeons and hospitals give the best after care instructions.  I know mine did not.  Until complications occurred and then I wawas suppose to have known what they had not told me or wrote down in the after visit summaries.  So I am including this section.

If you are preparing for the LIFT procedure and live longer than 20 minutes from the hospital that you have your surgery in,  start planning on a way to come home where you can have zero pressure on your buttocks.  After the LIFT procedure you should not sit nor stand for longer than 20 minutes for the first 2 weeks,  You should lay on your side not flat on your back,  You cannot lift more than 10 pounds, bend over or squat to do anything.  You have had your anus turned inside out, an incision on the side of the anus so the surgeon can stitch things up,  SO your anus has been sutured to fix the fistula, and near your anus has been sutured to repair where they opened to have entry to do the surgery.  Being delicate is needed.  Keep your bowels soft,  do not bear down hard or you can break sutures. and take time to rest so that you heal. 

While you are going through these surgeries and suffering from FCD most of us need to increase our Protien level. generally getting 1g to 1.5  of protien to 1 kg of body weight.  So if you weigh 200 pounds that would put your protien about 100 to 120 grams of protien.  Proper nutrition is needed for wound healing especially if you are on biologics which can delay wound healing and make you more suspectiable to developing infections.

If you are having drainage from your wound at anytime,  I reccomend using woven Gauze 4x4s.  Non woven  gauze especially if you have a seton, pezzer or penrose drains the loose fibers get caught up.  folding the woven gauze in half and placing inbetween your buttcheccks works very well.  I personally do not like pany liners but some people do.  and they have come a long way in becoming very thin.

Not immediately after surgery, but when the area is well healed if you have irritation from drainage or even still have a seton in place due to other things,  I cannot stress enough how much of a life saver Desitin creamy is.  It can take Perianal ulcers from prolonged fecal contact due to fistula drainage from angry and unbearable to tamed and gone in 48 hours.