From the Guidelines
The most common enteric fistula occurring due to Crohn's disease is the entero-enteric fistula (option A). This type of fistula forms between two segments of small intestine, allowing intestinal contents to bypass portions of the bowel. Entero-enteric fistulas develop as a result of the transmural inflammation characteristic of Crohn's disease, where the inflammatory process extends through all layers of the bowel wall. When adjacent loops of inflamed intestine come into contact, the ongoing inflammation can lead to adhesion formation, followed by ulceration and eventual fistulization between the two segments. While Crohn's disease can cause various types of fistulas, including enterocutaneous, enterovesical, and enterocolic fistulas, the entero-enteric type occurs most frequently due to the anatomical proximity of small bowel loops in the abdominal cavity and the predilection of Crohn's disease to affect the small intestine, particularly the terminal ileum. Management typically involves controlling the underlying Crohn's disease with immunosuppressive medications, biologics, or surgical intervention if medical therapy fails, as suggested by recent guidelines 1. Some studies have reported the use of seton drainage, fibrin glue, and fistula plugs as treatment options for enteric fistulas, with varying success rates 1. However, the most recent and highest quality study on the topic does not provide a clear answer to the question, but it does emphasize the importance of controlling the underlying disease in the management of fistulas 1. Key points to consider in the management of enteric fistulas include:
- Controlling the underlying Crohn's disease with immunosuppressive medications, biologics, or surgical intervention if medical therapy fails
- Using seton drainage, fibrin glue, and fistula plugs as treatment options for enteric fistulas, with varying success rates
- Considering the anatomical proximity of small bowel loops in the abdominal cavity and the predilection of Crohn's disease to affect the small intestine, particularly the terminal ileum, in the development of entero-enteric fistulas.
From the Research
Types of Fistulas in Crohn's Disease
- Enteroenteric fistula: a fistula that forms between two parts of the intestine 2, 3
- Enterocutaneous fistula: a fistula that forms between the intestine and the skin 4, 5
- Enterovesical fistula: a fistula that forms between the intestine and the bladder 2, 3, 5
- Enterocolic fistula: a fistula that forms between the small intestine and the colon, also known as ileosigmoid fistula 2
- Aortoenteric fistula: a fistula that forms between the aorta and the intestine 4
Prevalence of Fistulas in Crohn's Disease
- Internal fistulas occur in up to 15% of patients with Crohn's disease 2
- Enterocolic fistulas (ileosigmoid fistulas) occur in 6% of all Crohn's disease cases and 16-26% of cases with internal fistulas 2
- Perianal fistulas are the most prevalent type of fistula in Crohn's disease patients 4
Most Common Enteric Fistula
- The most common enteric fistula occurring due to Crohn's disease is not explicitly stated in the provided studies, but enteroenteric fistula is mentioned as one of the types of internal fistulas that can occur in Crohn's disease 2, 3
- However, it can be noted that enterocolic fistula (ileosigmoid fistula) is mentioned as occurring in 6% of all Crohn's disease cases and 16-26% of cases with internal fistulas 2