Explain the procedure and obtain consent. Check allergies and renal function. Position the patient, cleanse and drape the external opening. Cannulate the fistula with a small catheter, secure it, then gently inject water‑soluble iodinated contrast under aseptic technique, avoiding high pressure. Perform thin‑slice CT with multiplanar reconstructions to map the tract and collections. Monitor for contrast reactions, ensure hydration, and arrange wound care and follow‑up.

Yes—CT scans often detect fistulas, especially with contrast. CT can show abnormal air/fluid tracts, surrounding inflammation and associated abscesses; CT enterography is useful for intestinal fistulas. Small, superficial, or complex pelvic/perianal fistulas may be missed, and MRI or endoanal ultrasound is often more sensitive. Sometimes dedicated fistulography, endoscopy or combined imaging is needed to fully map the tract.

A fistulogram is an imaging test that injects contrast dye into an external fistula opening and uses X‑ray or fluoroscopy to map the tract’s course, length, branches and any internal connections (for example to bowel, bladder or abscess cavities). It helps diagnose extent and guide surgical or drainage planning. Performed by a radiologist, it may cause mild discomfort and carries small risks like infection or allergic reaction.

MRI pelvis (with contrast) is the preferred test for complex perianal fistulae — it maps tracts and sphincter involvement. For simple or low fistulae, endoanal (endorectal) ultrasound is accurate. Abdominal or enteric fistulae are best evaluated with contrast-enhanced CT (CT fistulography/enterography). Choice depends on location and complexity; clinical assessment guides imaging selection.

Before a CT scan you register, remove metal and change into a gown. Lie on the motorised table; staff position you and may insert an IV for contrast. The table moves through the gantry while you hold still and follow breathing instructions. Scanning takes seconds to minutes. Afterward you may be observed briefly if contrast was given and are advised to drink fluids.

A fistulogram typically takes about 30–60 minutes from start to finish. The imaging portion usually lasts 10–30 minutes after local anaesthetic and contrast injection, while setup and brief post-procedure checks add time. Some cases may take longer if access is difficult or extra views are needed. You can usually go home the same day.