If an anal fistula is in its acute phase, the main clinical symptoms are intermittent discharge of pus from the external opening, or pain and itching.

If there are no symptoms, and only the external and internal openings along with the fistula tract exist, surgery is still required because the absence of symptoms temporarily does not guarantee that an acute episode will not occur later. During an acute episode, there will be local tissue and skin inflammation, redness, heat, and severe pain. If an anal fistula is not surgically treated for a long time, it may lead to an increase in the number of branches of the fistula or thickening of the fistula wall, and it may even spread to the pelvic cavity.

Therefore, once an anal fistula is discovered, it is necessary to perform surgery as soon as possible. Early treatment has significant benefits for wound recovery and the difficulty of the operation.