Theoretically you can take sildenafil after hemorrhoid surgery because the main organ of action of sildenafil is far from the area where hemorrhoid surgery is performed.
Hemorrhoid surgery is mostly performed by excision, i.e. removing the dilated and flexed venous clusters at the end of the rectum and the venous plexus under the skin of the anal canal, which is mainly related to the digestive system; while sildenafil is mainly used for treating erectile dysfunction of the male penis, which is applied to the reproductive system rather than to the digestive system, and so it usually does not have any impact on the patients after the surgery. Therefore theoretically you can take sildenafil after hemorrhoid surgery.
If the patient postoperative medication, should be timely to the hospital by the doctor to guide the application, not to be taken lightly or self-treatment, so as not to delay the condition.