Intestinal Fistulas Treatment & Management

Updated: Mar 08, 2018
  • Author: David E Stein, MD, MHCM; Chief Editor: Burt Cagir, MD, FACS  more...
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Approach Considerations

2016 American Society of Colon and Rectal Surgeons recommendations

Anorectal abscess [13]

  • Prompt incision and drainage of an acute anorectal abscess
  • Cautious abscess drainage with concomitant fistulotomy for simple anal fistulas
  • Antibiotics reserved for complicated cases of anorectal abscess (eg, cellulitis, systemic infection, underlying immunosuppression)

Anal fistula [13]

  • Fistulotomy for simple anal fistulas in the setting of normal anal sphincter function
  • Endoanal advancement flaps foranal fistulas
  • Ligation of the intersphincetric tract (LIFT) procedure for simple and complex anal fistulas
  • Cautious use of a cutting seton in the management of complex cryptoglandular anal fistulas

Relatively ineffective treatments for anal fistulas include fistula plugs and fibrin glue. [13]

Perianal fistula associated with Crohn disease [13]

  • No surgical intervention required for asymptomatic fistulas in Crohn disease
  • Fistulotomy for symptomatic, simple, low anal fistulas in Crohn disease
  • Loose setons effective in multimodal treatment of fistulizing perianal Crohn disease; may also be used for long-term disease control
  • Endoanal advancement flap, anal fistula plug, and LIFT for treatment of anal fistula in Crohn disease
  • Potential need for permanent diversion or proctectomy for uncontrollable symptoms in complex Crohn fistulas

Rectovaginal fistulas [13]

  • Nonoperative management for the initial treatment of obstetric rectovaginal fistula; may be considered for other benign and symptomatic fistulas
  • Potential need for a draining seton potentially to help resolve acute inflammation/infection related to rectovaginal fistulas
  • Procedure of choice for most simple rectovaginal fistulas: endorectal advancement flap, with or without sphincteroplasty
  • Episioproctotomy for repair of obstetric or cryptoglandular rectovaginal fistulas associated with extensive anal sphincter damage
  • Gracilis muscle or bulbocavernosus muscle (Martius) flap for recurrent or complex rectovaginal fistula
  • Potential need for an abdominal approach repair for high rectovaginal fistulas caused by complications of a colorectal anastomosis
  • Potential need for proctectomy with colon pull-through or coloanal anastomosis for repair of radiation-related and recurrent complex rectovaginal fistula

Treatment considerations

Several elements are required to successfully treat patients with an intestinal fistula: adequate nutrition, control and maintenance of the fistula drainage site, appropriate treatment of infection, and avoidance of sepsis. [18, 19, 20]

Spontaneous closure of a proportion of gastrointestinal (GI) fistulas with nonoperative management is well documented. Although dependent on the etiology of the fistula, 60% or more close if they are iatrogenic, if no distal obstruction is present, if no foreign body is involved, if the tract is long, if there is a low output, and if there is no active infection. Numerous studies have delineated the important determinants associated with decreasing the time to closure of a fistula and decreasing a patient's overall associated morbidity and mortality.

Conservative management of enteric fistulas has been described for periods of up to 3 months. [21] One study demonstrated that 90% of the fistulas that spontaneously closed did so within the first month, once management of sepsis had been established. [19] Of note, none of the fistulas spontaneously closed after 3 months.

Factors to consider for fistulas that do not spontaneously close include the following:

  • Malignancy
  • Foreign bodies in the fistula tract
  • Short fistula tracts with epithelialization
  • Undrained abscess cavities
  • Distal obstruction
  • Radiation enteritis
  • Active inflammatory bowel disease of the involved bowel segment
  • High-output status for the fistula

In these cases, surgical repair may be the definitive treatment. [22]  (See the image below.) However, it is important to consider the timing of such surgery. A systematic review and meta-analysis of 15 studies regarding the timing and outcome of intestinal failure surgery in patients with enteric fistula found lower recurrence rates in the setting of a longer median time and/or a longer time interval to surgery, and an overall 3% mortality. [23]  The optimal timing for operative intervention could not be defined owing to each study's wide range of time to definitive surgery.

Status postpancreatic debridement for necrotizing Status postpancreatic debridement for necrotizing pancreatitis. The patient had a colonic injury with attempted closure using a skin graft. The patient later underwent definitive repair.

Endoscopic managment is also being considered in for gastrointestinal transmural defects, such as fistulas. [14, 15]  In a retrospective study (2015-2016) that assessed the feasibility, safety, and efficacy of endoscopic-guided gastroenterostomy or enteroenterostomy with a lumen-apposing metal stent (LAMS) in 13 patients undergoing reestablishment of bowel continuity following resection and bypass of diseased or obstructed GI tract, investigators reported all patients but one had technical and clinical success. [14]

Enterocutaneous fistulas

A meta-analysis of the literature by Rahbour et al suggested that somatostatin and its analogs are effective in the treatment of enterocutaneous fistulas. [24]  Among patients in the somatostatin group and those in the analog group, fistulas were more likely to close, and to do so faster, than they were in the control group, although comparison with the controls suggested that neither somatostatin nor its analogs affect mortality. Because the risk ratio for somatostatin was higher than that for the somatostatin analogs, it may be that somatostatin can close more fistulas, and do so more quickly, than its analogs. [24]

In a retrospective review of 48 Crohn disease patients with enterocutaneous fistula, Amiot et al found that anti-tumor necrosis factor (anti-TNF) therapy may be effective in up to one third of such patients, particularly those without complex fistulas and stenosis. [25] The study, which had a median follow-up period of 3 years, involved patients with enterocutaneous fistulas of the small bowel, duodenum, or colon (those with perianal fistulas were excluded). Fistulas closed completely in 16 patients (33%), although eight of these individuals relapsed during the follow-up period. Multivariate analysis linked lack of complete fistula closure to the presence of multiple fistula tracts and associated stenosis. [25]

Stem cell therapy, as well as infection of mesenchymal stem cells, appear to have potential in managing refractory perineal Crohn disease. [20, 26, 37]


The following consultations can aid in treatment:

  • Nutritionist
  • Enterostomal or wound care nurse
  • Surgeon: Gynecologic or urologic surgeon if the fistula involves either the vagina or the bladder


In the initial period, patients are maintained on total parenteral nutrition (TPN) and are given nothing by mouth (NPO).

In patients with low-output, distal fistulas, elemental diets may be initiated as long as they do not profoundly increase the fistula output.


Aggressive physical therapy provides long-term benefits to patients. Typically, patients do not require prolonged bedrest (which only adds to comorbidities) unless this is necessary for some other reason.



Initial fistula management should address each of the following resuscitation and stabilization issues in patients with a gastrointestinal (GI) fistula. [27]


Total parenteral nutrition (TPN) has long been regarded as an essential therapy (especially in high-output fistulas) to decrease output and to maintain good nutritional status.

Malnutrition is a significant cause of morbidity and mortality, especially with enterocutaneous fistulas. Typically, patients with low-output (< 200 mL per 24 h) fistulas should receive their full resting expenditure, 1-1.5 g of protein/kg daily and a lipid intake that accounts for approximately 30% of daily caloric intake. Patients with high-output (>500 mL per 24 h) fistulas should receive 1.5-2 times their resting energy expenditure, 1.5-2.5 g of protein/kg daily, and twice the recommended daily allowance of lipids.

Skin care and drainage control

Control of enteric contents draining from the fistula continues to be a topic of ongoing research and development. Standard ostomy supplies and other methods of skin care and drainage control can be used in an attempt to reduce or eliminate the persistent tissue inflammation and infection surrounding the fistula, which can lead to sepsis. [28] Use of the vacuum-assisted closure (VAC) device to better manage output has been reported to help improve the perifistular environment. [29] Furthermore, application of VAC with negative pressures up to –125 mm Hg has demonstrated to be effective management prior to surgical treatment. [30]  All of these techniques and devices are used not to close the fistula, but rather to help keep the surrounding tissues healthy and to allow the fistula to heal on its own. Another potential conservative option includes the use of fibrin glue for low-output fistula tracts. [31]  This technique, although not a current standard treatment, has achieved some success in promoting closure of enterocutaneous fistulas.

Identification and drainage of fluid collections

The use of computed tomography (CT) scanning and ultrasonography can help to determine if fluid collections or abscesses are present along the abscess tract. Identification of these fluid collections often allows for CT-guided drainage of these loci to prevent infection. Along with better drainage control and appropriate antibiotic treatment, this helps to decrease the morbidity and mortality associated with enteric fistulas and allows for a safer period of conservative management. Radiologically placed catheters have been demonstrated to safely and successfully drain most abscesses.

Fluid volume depletion

In patients with proximal, high-output fistulas, the volume depletion associated with the drainage can be a significant problem. Whether medications such as octreotide (a synthetic substitute of somatostatin that suppresses the release of many GI hormones) help to close fistulas remains unclear. [32] Research has demonstrated significant and nonsignificant effects of medication on the closure of fistulas, yet these studies agree that octreotide does decrease overall fistula output. [32]


Resection and Anastomosis

The period of nonoperative management of an enteric fistula, while allowing for spontaneous closure of the fistula, also provides time to optimize nutritional status and to heal the wound site from the patient's initial surgery (if the enteric fistula occurred postoperatively). Thus, definitive surgery for fistula repair is generally delayed for several months until physiologic deficits have been restored and intra-abdominal conditions are less hostile. However, if diffuse peritonitis with ongoing sepsis is observed, immediate operative exploration may be necessary to stabilize the patient.

The preferred procedure involves excision of the fistula tract, with segmental resection of involved bowel and anastomosis of the remaining bowel. [33] If an unexpected abscess is encountered or the quality of the bowel wall is suboptimal, some surgeons may consider a primary anastomosis unsafe, instead choosing to perform a staged procedure, with exteriorization of the ends of the bowel during the first procedure. A staged repair may also be more appropriate in cases in which advanced malignancy or severe radiation changes are expected. If the procedure is performed for a malignancy, preferably, the involved segment of bowel is removed to negative margins.

The abdominal wall may not be able to be closed due to a lack of fascia. In these cases, biologic meshes, which are manufactured from porcine or bovine dermis, human cadaveric dermis, or porcine small intestinal submucosa, may be used to help close the abdominal cavity. These meshes are not at risk for infection.

Perianal abscesses should be drained and anal strictures dilated. Patients with low anal fistulas can be treated with fistulotomy. Some surgeons are in favor of a noncutting seton, especially in the presence of an active inflammation of the rectosigmoid colon. Noncutting setons may be placed in fistula tracts in patients with rectal inflammation, and endorectal advancement flap procedures for high perianal fistulas and rectovaginal fistulas may be performed in patients without rectal inflammation. Another option that preserves sphincteric function is using a fistula plug, which provides a matrix for soft-tissue healing. [34, 35]

If a rectovaginal fistula persists after the patient has received medical therapy and anorectal stricture or active rectal disease is not evident, then surgical repair may be performed with either (1) transanal or transvaginal advancement flaps or (2) laparotomy with primary closure or sleeve advancement flap. [36]

Patients with colovesical fistulas can almost always be treated with resection of the involved segment of colon and primary reanastomosis, with or without closure of the bladder defect. Healing of the bladder is usually managed easily with temporary urethral catheter drainage.

The overall incidence of aortoenteric fistulas has changed with the advent of endovascular repairs of abdominal aortic aneurysms, but the criterion standard remains open excisional repair and extra-anatomic bypass for revascularization in the case of secondary aortoenteric fistulas (which occur after open repair of abdominal aortic aneurysms). Endovascular repair of primary aortoenteric fistulas in high-risk patients (ie, those at risk for chronic infection of the endograft) has been reported.


Intestinal fistulas carry high morbidity and mortality rates. If medical and nonoperative treatments are not effective, the risks of surgery need to be discussed with patients and their families.

Complications are routine, as dense, fibrotic adhesions are likely to be encountered during surgery. Infection, bleeding, and injury to adjacent organs, as well as recurrence of the fistula, are all possibilities. To reduce these complications, patients must receive optimal nutrition and must be treated by an experienced surgeon.



Follow-up care is based on disease etiology. In patients with chronic inflammatory conditions, such as Crohn disease, ongoing follow-up care is required.

If patients are simply waiting for definitive surgical therapy and being maintained on total parenteral nutrition, they do not need to be in the hospital. Home infusion or placement in a rehabilitation facility is perfectly acceptable. Close contact is needed, as line sepsis and other infectious complications may occur, and early and aggressive treatment is essential to ensure a good outcome.

In patients who have undergone surgical repair, normal postoperative follow-up care is required. Once the incisions are healed and the drains are removed, the patient may be discharged from care.

Patients with Crohn disease may require ongoing outpatient maintenance therapy with medication.