Hi yes it's possible for an abscess to be almost anywhere back there. Yes it is possible for healing without surgery. Everything done is at one's own risk and everyone is in charge of their own health care.
Diarrhea and constipation must both be avoided like the plague. After each bowel movement careful wiping with a very soft tissue or with a large cotton facial make-up wipe was used.
Somebody did hydrotherapy such as a warm water pour followed by a little cool water after every bowel movement. A hair dryer was used to help prevent germs from being transferred around with a towel.
A steam activated charcoal poultice was placed on the painful area to help with pain and to draw poisons of the infection out of the area. Two tablespoons steam activated charcoal can be mixed with a little water and 2 tablespoons flax.
The charcoal and flax can then be simmered together until there is a paste. The charcoal paste can then be placed in a paper towel to within an inch of the edge. The poultice can then be taped on the area with cloth hypoallergenic tape. If preferred it can be left on at night. Since it does help with pain perhaps it will be desired in the day. In winter the poultice can be kept in place with a thermal underwear as well tape.
When the site reached the point where there seemed to be no major infection or bleeding anymore and no boil like thing anymore a tea tree oil suppository was gently placed in the anus. After 20 minutes or less, a plug was placed between bowel movements using a large square of saran wrap and olive oil with a tiny water balloon no bigger than the size of the intestine and put the plug back in after each bowel movement to keep the tracts blocked from bowel movement entering the tract again. (if the water balloon is too large it will not go in). This helps keep bowel movements out of the tract until completely healed up. This must be done gently with no pain.
The rest of the saran wrap is left out as a tail so that it may be easily pulled out at the time of the bowel movement with a hand protected from bowel movement with a sandwich bag. Hands were washed after the bowel movement. A brazil nut inside the water balloon was used inside the water at first to help insert and later skipped because it was more comfortable and it was found that inserting it could be done without the nut with practice. Sitting was done with one side lifted up or hanging or a chair until well healed. This may not work if the tracts are too high.
Usually the medical profession will say not to do this for possible worsening, they do not advise putting anything at all up in the anus. Some people have said there is risk of worse infection with even death if there is anaerobic bacteria trapped by a plug. The risk was taken because of fears of surgery and a wish to avoid incontinence, infection and pain that many seem to suffer after surgery. The olive oil was said to be antibacterial. Looking at the structure of olive oil it was supected that the oil might also keep the plastic bag a bit away from the bowel. Olive oil also has oxygen in it so it was thought the anaerobic problem might not be a problem.
When bowel movements were had pushing them out was not allowed. To help with the pushing reflex panting was done not quite like a pregnant woman so intrabdominal pressure was avoided. When bowel movements were done a plastic sandwich bag was used to protect the hand and gentle pressure to block the tracts during the pass were done and then thrown out, a new sandwich bag is used each time and is cheaper than gloves.
There is risk that the pressure can move infection to other places. Of course all health choices are ones own and some people have had good results with surgery and some have not. One story had it that a seton was placed in someone and it was there for years. Some people have had blood and pus months or more later, others have had their setons come out later with good healing.