The most important thing is that you have to take a fumigation bath after the anal fistula surgery, and the water in the fumigation bath will be added with potassium permanganate, the concentration should be moderate. The color of the water is generally pink concentration is about the same, the sitz bath is generally carried out after the stool, after the stool with water to clean the anus and then sit the anus into the basin with potassium permanganate water, the temperature should be appropriate, the time is generally about 10-15 minutes, the frequency can be carried out once in the morning and once in the evening, but also once a day after the stool. The thing to note about potassium permanganate baths is that the concentration should not be too high, because too high a concentration may burn the skin around the anus. There is also a situation where potassium permanganate baths can form pigmentation in the anal opening over time. Therefore, patients who use potassium permanganate sitz baths should not take them for too long. The actual fact is that if you are still taking a sitz bath for more than a month, it is likely to lead to pigmentation of the skin around the anus.