An enterovesical fistula (EVF) is a connection between the lumens of the intestines and the bladder. It is an abnormal and rare condition that is usually secondary to another gastrointestinal condition, such as cancer or trauma.
An enterovesical fistula (EVF) is a communication between the lumen of the bladder and any part of the intestines. EVF occur due to a number of factors that include infection, abdominal trauma, malignancies, chronic inflammation and surgery.
The most common form of EVF is a colovesical fistula. Rectovesical fistulae are more often observed after surgical procedures. Some larger EVF develop a system of numerous channels, frequently complicated by abscess formation, and the development of bowel obstruction .
Symptoms of EVF consist of both urinary and gastrointestinal complaints, which may occur simultaneously with those of the primary etiology . Urinary symptoms include suprapubic pain, pneumaturia, and signs of fecal contamination of the urogenital tract, such as recurrent urinary tract infections, debris, foul smelling urine, fever and sepsis   . Gouveneur’s sign, which is frequency, dysuria, tenesmus and suprapubic pain, is highly suggestive of EVF . Fecaluria is confirmation of the presence of an EVF, however pneumaturia can occur due to infections by certain micro-organisms.
The diagnosis of EVF, initiated by clinical evaluation, is a challenge as there is no standard workup. Therefore, a significant part of investigation and management is dependent on medical imaging. Imaging can give information about the location of the fistula, as well as complications that may arise, exemplified by abscess or stricture formation . Possible imaging modalities include:
Poppy seed test: Patients are asked to ingest 50 grams of poppy seeds, which are excreted in urine within a few days, confirming an EVF. Its detection rate is near perfect . It cannot, however, indicate the location of the fistula or what part of the bowel is involved.
Biochemical testing may involve: