Related diseases

Anal Fistula

Anal Fistula

What is Anal Fistula?

Anal fistula is tiny inflammatory tract connecting anal skin with rectal wall. This tract is formed after the acute infection and abscess formation of the anal crypt gland.

Underlying causes

Anal fistula is mainly caused by purulent bacterial infection. Some anal fistula are resulted from Crohn's disease, ano-rectal trauma secondary infection or malignancy.

Main clinical symptom

  • Lump found and redness around the anal area occasionally
  • Varying size of lump
  • Secretion of pus or bleeding etc


Surgery, called "fistulectomy" or "fistulotomy" is required.
1. Find the external opening in the skin around the anus.
2. Find the internal fistula opening by inserting a probe or H2O2 instillation from the external opening along the fistula tract. The whole fistula tract can then be cut or remove.
3. During surgery, surgeons will try to preserve the anal sphincter and prevent fecal incontinence.