If you have a feeling of swelling 1 month after hemorrhoid surgery, consider the following situations: 1. Local edema after surgery is a common post-operative complication. 2. Bacterial infection at the surgical incision, resulting in inflammation and swelling and other symptoms, you need to choose to use potassium permanganate solution diluted in a sitz bath, which can play a bactericidal and anti-inflammatory effect, and apply erythromycin ointment on the affected area to assist in treatment. 3. The scarring that occurs after surgery can cause a feeling of swelling and foreign body in the anal area, and in a few cases, it can be accompanied by pain. You should pay attention to maintenance after hemorrhoid surgery, change the medication regularly, keep the affected area clean and hygienic, and go to the hospital in time if there is an abnormality.