An intestinal fistula is an abnormal connection that forms between the intestine and another organ or the skin. This passage allows intestinal contents to leak into areas where they do not belong. It is considered a complication of an underlying disease, a surgical procedure, or an injury.
Understanding Intestinal Fistula Types
Intestinal fistulas are categorized based on their location, output, and complexity. For instance, an enteroenteric fistula connects two different parts of the intestine, while an enterocutaneous fistula creates a pathway from the intestine to the skin. Other types include enterovesical fistulas, linking the intestine to the bladder, and enterovaginal fistulas, connecting the intestine to the vagina.
Fistulas are also classified by their output volume, differentiating between high-output and low-output fistulas. High-output fistulas typically drain more than 500 milliliters of fluid per day, while low-output fistulas drain less. Additionally, fistulas can be described as simple or complex, depending on the number of openings, associated conditions like abscesses, or involvement of multiple organs.
Common Causes of Fistula Formation
Intestinal fistulas most frequently arise as a complication following abdominal surgery, accounting for 75% to 85% of cases. These can result from issues like leaks at surgical connection points or unintended injury to the bowel during a procedure. Inflammatory bowel diseases, particularly Crohn’s disease, are another common cause, as the chronic inflammation can lead to deep ulcers that penetrate the bowel wall and connect to adjacent structures. Up to 40% of individuals with Crohn’s disease may develop a fistula.
Infections and abscesses within the abdomen can also lead to fistula formation. Severe cases of diverticulitis, where inflamed pouches in the digestive tract rupture, can erode into neighboring organs and create a fistula. Abdominal trauma, such as stab or gunshot wounds, can directly injure the intestine. Radiation therapy, often used for cancer treatment, can cause long-term tissue damage and inflammation, increasing the risk of fistula development months or even years later. Tumors can also cause fistulas by eroding through the bowel wall and into adjacent organs.
Recognizing Symptoms and Getting Diagnosed
The presence of an intestinal fistula can manifest through various symptoms, which often depend on the fistula’s location. Common indicators include abdominal pain and tenderness, often accompanied by fever and chills, which can signal an infection. Nausea, vomiting, diarrhea, weight loss, and malnutrition are frequently reported due to improper nutrient absorption.
For fistulas connecting to the skin, there is noticeable drainage of intestinal contents from an opening on the skin. If the fistula connects to the bladder, individuals might experience recurrent urinary tract infections, or even gas or stool in their urine. A connection to the vagina may result in vaginal discharge containing gas or stool.
Diagnosis involves a physical examination, a review of symptoms, and crucial imaging tests to identify the fistula’s exact location and extent. These include CT scans, which can show the fistula and any associated abscesses, and MRI scans. A fistulogram, where dye is injected into an external opening and X-rays are taken, helps visualize the tract. Barium studies, where a contrast liquid is swallowed or administered as an enema, can also reveal leaks in the intestines. Blood tests assess overall health, nutritional status, and signs of infection.
Managing and Treating Intestinal Fistulas
Treatment for intestinal fistulas is often multi-faceted, beginning with medical management to stabilize the patient and encourage spontaneous healing. Nutritional support is a cornerstone of this approach, frequently involving parenteral nutrition (intravenous feeding) or enteral nutrition to ensure adequate caloric and protein intake. Fluid and electrolyte imbalances, common due to fluid loss through the fistula, are carefully managed to prevent dehydration.
Medications play a role in managing symptoms and complications. Antibiotics are used to treat infections, while anti-diarrheals may help control excessive fluid output. For external fistulas, diligent wound care is necessary to protect the surrounding skin from irritation caused by digestive fluids. Some simpler fistulas, especially those with low output, may close on their own with consistent medical support, often within 4 to 6 weeks.
Surgical intervention becomes necessary when medical management fails, or for complex fistulas that are unlikely to heal spontaneously. Surgery aims to remove the diseased segment of the intestine, close the abnormal connection, and reconnect healthy bowel segments. Early surgery may be considered in cases of uncontrolled infection or complete intestinal obstruction. The decision for surgery is made after optimizing the patient’s overall health.