For anal fistula, many patients are often unbearable, especially the pain caused by the flow of pus and feces, it is indescribable anal fistula is not healed, the main reasons are: 1, the presence of the internal mouth The key to treating anal fistula is to find the internal mouth, if the internal mouth is missing, the primary source of infection such as anal sinusitis, or anal gland infection still exists, the contents of the intestinal cavity can continue to enter the fistula from the internal mouth, again forming a new fistula. This is the key to the recurrence of anal fistula. The actual fact is that you can find a lot of people who are not able to find all of the fistulas, but just eliminate the surface of the fistulas, and not solve the most critical internal ports, resulting in repeated attacks of anal fistulas. It is not conducive to the adhesion of the fistula. The fecal matter, intestinal fluid and gas continue to enter the fistula and stimulate the wall, making the connective tissue of the wall thicken and make it difficult to close the lumen. What are the causes of anal fistulas that do not heal? The reason for this is multifaceted, and the common clinical reasons are: 1, the surgery did not accurately find the inner mouth, or the treatment of the inner mouth is incorrect, resulting in a false inner mouth; or even if the inner mouth is accurately found, but not thoroughly remove the infected anal sinus, anal glands and the primary lesions of the internal sphincter, can also lead to poor healing. 2, rush surgery when the sinus tract has not yet formed, so that the inflammation spreads, forming new sinus tracts and pus cavities and affecting healing. 3, due to fistula bending, intraoperative fistula caused by false fistula or fistula was residual, or fistula necrotic tissue within the scratch is not clean, resulting in difficult healing and recurrence of the traumatic mouth. 4.A gap or dead space is left in the wound suture, or the suture tension is too large. 5.Foreign objects, such as threads, cotton wool, etc., are left in the wound opening and are buried by the surrounding granulation tissue, which affects the normal growth and healing of the wound opening. 6. The patient is excessively weak or has chronic diseases such as diabetes, tuberculosis, leukemia or anemia, which makes the wound difficult to heal for a long time. In order to prevent the occurrence of the above, the lesion should be thoroughly removed during surgery, as well as eliminate factors that are not conducive to wound healing, and prevent wound infection after surgery by continuously using antibiotics for one week, while keeping the wound drainage unobstructed.