A little hardness next to the wound 40 days after the complex anal fistula hanging surgery may be related to normal phenomenon, proliferation of tissues, formation of abscess, recurrence of anal fistula and other circumstances. 1. Normal phenomenon: complex anal fistula thread may take about a month to fall off, after the shedding of the wound area of the tissue will grow new buds, touch may be different from the surrounding skin touch. 2. hyperplasia: if the patient belongs to the keloid body, when the hanging line falls off, the tissue will gradually appear connective hyperplasia, the formation of hard to the touch, the color of purple and red hyperplasia. 3. Formation of abscess: in the treatment process, if you do not pay attention to hygiene and anti-inflammatory, may lead to secondary infection in the area, and then form abscesses, abscesses are generally hard to the touch, can be pushed, there is a clear sense of pain. 4. anal fistula recurrence: anal fistula is very likely to recur, once recurrence, can be manifested as a hard lump in the perianal area, accompanied by perianal moisture, perianal itching and other symptoms. It is recommended that the patient regular postoperative medical examination, such as abnormal phenomena, timely diagnosis and treatment, follow the doctor’s instructions.