Anal Fistula
An anal fistula is an abnormal tunnel that forms between the inside of the anal canal and the skin near the anus. It often develops due to an infection in an anal gland, which can cause an abscess (a pocket of pus) that drains to the skin. When the abscess heals incompletely or reopens, it can leave behind a fistula.
What Causes an Anal Fistula?
• Anal abscess: Most anal fistulas develop from an untreated or inadequately treated anal abscess.
• Crohn’s disease: An inflammatory bowel disease that can cause ulcers or fistulas in the digestive tract.
• Infections: Certain infections like tuberculosis or sexually transmitted infections (e.g., chlamydia) can lead to fistulas.
• Trauma: Injury to the anal or rectal area may lead to a fistula.
• Radiation therapy: Rarely, radiation treatment for cancers of the pelvic area can cause a fistula.
Symptoms of Anal Fistula
• Recurrent abscesses: Constant or repeated infections near the anus.
• Discharge: Pus or blood draining from an opening near the anus, often accompanied by a foul smell.
• Pain and Swelling: Pain around the anus, especially when sitting, moving, or passing stool.
• Irritation: Skin irritation or redness around the anal opening.
• Fever or Malaise: If the fistula is infected or causes an abscess.
Diagnosis of Anal Fistula
• Physical Examination: A healthcare provider will often be able to diagnose a fistula through a physical exam, especially if the external opening is visible.
• Anoscopy: A small scope may be inserted into the anus to visualize the inside of the anal canal.
• Imaging Tests: In complex cases, imaging tests such as MRI or endoanal ultrasound may be used to determine the exact location and extent of the fistula.
Treatment Options for Anal Fistula
1. Surgical Treatment
Surgery is usually necessary to treat an anal fistula, as it rarely heals on its own.
• Fistulotomy: This is the most common procedure. The fistula tract is surgically opened and flattened to allow healing from the inside out. This is typically done for simple fistulas.
• Seton Placement: A seton (a surgical thread) may be placed through the fistula to keep it open, allowing it to drain and preventing infection while promoting healing over time. This is often used for complex or high fistulas.
• Advancement Flap Procedure: In this more advanced technique, the surgeon removes the fistula and covers the internal opening with a flap of healthy tissue from the rectum. This is used in complex cases where there is a high risk of incontinence.
• Fibrin Glue or Plug: In some cases, surgeons may inject a glue or place a plug made from collagen to close the fistula. These methods are less invasive but may not be as effective as surgery.
Post-Surgery Care
• Wound Care: Keep the surgical area clean and dry. Sitz baths (sitting in warm water) can help ease discomfort and promote healing.
• Pain Management: Your doctor will likely recommend pain relievers and stool softeners to make bowel movements less painful.
• Follow-Up Appointments: It’s important to attend follow-up appointments to monitor healing and prevent complications.
​
Preventing Anal Fistulas
While not all anal fistulas can be prevented, reducing your risk involves:
• Treating anal abscesses early: Prompt treatment of anal infections can prevent them from turning into fistulas.
• Managing Crohn’s disease: Proper management of inflammatory bowel diseases can reduce the risk of fistulas.
• Good Hygiene: Maintaining cleanliness in the anal area can help prevent infections.
When to Seek Medical Help
Contact your healthcare provider if you experience:
• Persistent or severe pain in the anal area
• Recurrent swelling or abscesses
• Foul-smelling discharge or pus near the anus
• Fever, which may indicate infection
Conclusion
An anal fistula can be uncomfortable and recurrent, but it is treatable with proper medical or surgical intervention. If you suspect an anal fistula, early diagnosis and treatment are key to avoiding complications and promoting healing.