بسم الله الرحمن الرحيم Bowel Fistula ــــــــــــــــــــــــــــــــــ Dr.Saad Al-Qahtani Department of surgery College of medicine, King Saud University

 Fistula is a communication between two epithelized surfaces.  Can be categorized according to: 1. anatomy. 2. outpot. 3. character of the tract.

1-Anatomy  External (enterocutenous or rectovaginal fistula).  Internal (colovesical or enterocolonic fistula ).

 Proximal( upper GI, ass with high output and sever symptoms & sequalae, &poor prognosis).  Distal ( ileum, colon &rectum. Less complication, often close non- operatively).

2-Output  High output more than 500 ml/ day more than 500 ml/ day  Low output less than 200 ml/day less than 200 ml/day

3-Character of the tract.  Simple ( single tract )  Complicated.

Causes  Most small intestinal fistulas (75-80%) occur as a complication following surgery for abdominal malignancy, inflammatory bowel disease, tuberculosis or adhesiolysis.  The most common surgical causes of fistula formation include anastomotic dehiscence after bowel resection and injury to the bowel.  The rest of the small intestinal fistulas (20-25%) include the spontaneous type seen in inflammatory bowel disease, radiation, diverticular disease, ischaemia and malignancy.

Essentials of Diagnosis  Fever and sepsis.  Abdominal pain.  Localized abdominal tenderness.  External drainage of small bowel contents.  Dehydration and malnutrition.

Pathophysiology  Loss of GI contents. -hypovolemia. -hypovolemia. -acid-base & electrolytes disturbance. -acid-base & electrolytes disturbance.  Malnutrition.  Sepsis.

Assessment 1-Contrast radiography -most commonly used. -fistulogram for mature fistula(7-10dys). -oral contrast show the extravastion & is good for internal fistula & distal obstruction. -contrast enema for rectal &colonic fistula. -pyelography & cystography in case of urinary tract involved.

2. Endoscopy Help to know the coexistent dis e.g :Peptic ulcer, IBD 3-CT abdominopelvic To evalute presence of abscess.

Factors preventing spontaneous closure of small intestine fistulas  FRIEND Foreign body within the fistula tract Foreign body within the fistula tract Radiation enteritis Radiation enteritis Infection/Inflammation at the fistula origin Infection/Inflammation at the fistula origin Epithelialization of the fistula tract Epithelialization of the fistula tract Neoplasm at the fistula origin Neoplasm at the fistula origin Distal obstruction of the intestine. Distal obstruction of the intestine.

Management

First : Restore blood volume and begin correction of fluids and electrolyte imbalance. Drain accessible abscesses. Control fistula and measure losses. Begin nutritional support. Second: Delineate anatomy of fistulas by radiographic studies. Third: Maintain caloric intake of 2000–3000 kcal or more per day, depending on status of nutrition and energy expenditure. Drain abscesses as they appear. Fourth: Operate if fistula fails to close after 2-3 mths.