An abscess develops in short-term and is manifested by a painful and typically increased swelling in the anal region. Fatigue and increased body temperature may be added, particularly with larger abscesses. The treatment of choice consists in the opening of the abscess cavity and creating a generous runoff. Thus, a rapid ease of complaints is reached. Most surgery requires general anesthesia, smaller superficial abscesses may be opened under local anesthesia on an outpatient. The anal abscess always requires surgical treatment. Decongestants measures alone or the intake of antibiotics delay the healing process and can lead to serious complications. During the operation, an attempt is made to find the cause of the abscess, The reason is often an anal fistula. Is it possible to prove this, a thread is pulled through the canal and marks the anal fistula, the reason of the abscess, and drained (Thread drainage). This thread does not interfere with the patient and usually prevents re abscess formation and facilitates the identification of the fistula at the often necessary second operation. This second operation can be performed after 6 weeks.