From the Guidelines
The most common type of enteric fistula occurring due to Crohn's disease is the enterocutaneous fistula, which forms between the bowel and the skin. This is based on the evidence from the British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults 1. The guidelines discuss the management of enterocutaneous fistulae, which are a common complication of Crohn's disease, and highlight the importance of a multidisciplinary approach to managing these fistulas. Other types of fistulas that can occur in Crohn's disease include:
- Enterovesical fistulas (bowel to bladder)
- Enterovaginal fistulas (bowel to vagina)
- Perianal fistulas These fistulas develop as a result of the deep ulcerations and inflammatory process that are hallmarks of Crohn's disease, which progressively erode through tissue layers until they create abnormal passages. Management typically involves a combination of medical therapy (including biologics like anti-TNF agents, immunomodulators, and antibiotics) and sometimes surgical intervention depending on the severity, location, and complications associated with the fistula, as discussed in the ECCO-ESCP consensus on surgery for Crohn's disease 1. It's worth noting that the classification, diagnosis, and treatment of perianal fistulising Crohn's disease have been the subject of a global consensus, which highlights the importance of a multidisciplinary approach to managing these complex fistulas 1. However, the most recent and highest quality evidence suggests that enterocutaneous fistulas are the most common type of enteric fistula occurring due to Crohn's disease 1.
From the Research
Types of Enteric Fistulas in Crohn's Disease
- Enteroenteric fistula: a connection between two parts of the intestine 2
- Enterocutaneous fistula: a connection between the intestine and the skin
- Enterovesical fistula: a connection between the intestine and the bladder
- Enterocolic fistula: a connection between the small intestine and the colon, also known as ileosigmoid fistula
Prevalence of Enteric Fistulas in Crohn's Disease
- Internal fistulas occur in up to 15% of patients with Crohn's disease 3
- Enteroenteric fistulas are common in Crohn's disease, but their exact prevalence is not well-established 2
- Enterocolic fistulas, such as ileosigmoid fistulas, occur in 6% of all Crohn's disease cases and 16-26% of cases with internal fistulas
Characteristics of Enteric Fistulas in Crohn's Disease
- Enteroenteric fistulas often give few symptoms and their precise identification is not important in clinical management 2
- Enterovesical fistulas may respond well to anti-tumour necrosis factor therapies 3
- Perianal fistulas are the most prevalent type of fistula in Crohn's disease patients, but are not the focus of this question 4