Anal black is a normal physiological phenomenon caused by pigmentation during long-term defecation, patients do not need to worry too much, they just need to keep the area around the anus clean and dry in ordinary daily life, if there is pain or blood in the stool should promptly go to the hospital for examination, a clear diagnosis and then active treatment, can avoid delaying the disease, leading to adverse complications, if it is due to anal eczema If the anus is blackened. You can use topical medications such as mometasone furoate cream, you can also use compound bitter ginseng lotion to sit in the bath, for serious anal eczema caused by anal black, consider to surgically remove part of the skin to allow it to heal again, and then after defecation patients should pay attention to wash the anus with warm salt water, which will make the anus cleaner.