A defecography — also called a defecating proctogram — is a specialised fluoroscopy study used when the question is "what happens in your pelvic floor when you try to pass stool?" No other imaging test can answer this question as directly. The radiologist watches in real time while you defecate barium paste from your rectum, and the recording shows whether the pelvic floor muscles relax properly, whether the rectum empties completely, and whether anything is prolapsing.
It is a less commonly requested study than barium swallow or barium enema, but for the right patient — those with chronic constipation, incomplete emptying, or suspected pelvic floor prolapse — it can be the most useful investigation available.
Common Indications for Defecography
Your doctor may request a defecography if you have:
- Chronic constipation that has not responded to medical treatment.
- A sense of incomplete emptying after using the toilet.
- Needing to press on the perineum or vagina to help passage of stool (digital splinting).
- Faecal incontinence or leakage.
- Suspected rectocele, enterocele, or rectal prolapse.
- Painful defecation without a clear anatomical cause on colonoscopy.
What exactly does defecography show?
The test specifically demonstrates:
- Pelvic floor coordination — whether the puborectalis muscle relaxes during defecation. Failure to relax (dyssynergia or anismus) is a treatable cause of constipation.
- Rectocele — an outpouching of the rectal wall into the vagina. Larger rectoceles can trap stool and cause incomplete emptying.
- Enterocele — small bowel descending into the space between the rectum and vagina during straining.
- Rectal intussusception — telescoping of the rectum on itself during defecation.
- Rectal prolapse — full-thickness protrusion of the rectum through the anus.
- Perineal descent — abnormal lowering of the pelvic floor with straining.
What happens during the procedure?
The test is intimate but methodical, and the imaging team is experienced in keeping it as dignified as possible:
- You change into a gown and remove underwear.
- You lie on your side on the X-ray table.
- The radiographer gently inserts a small amount of thick barium paste into the rectum through a soft tube. In women, a small amount of contrast may also be placed in the vagina, and sometimes a thin barium drink is given an hour beforehand to outline the small bowel.
- You then sit on a specialised radiolucent commode placed on the X-ray table, in the upright position.
- The radiologist takes images at rest, while you squeeze the pelvic floor, while you strain (push down), and while you actually pass the barium.
- You are asked to evacuate as completely as possible into the commode while X-ray video is recorded.
The whole test typically takes 30 to 45 minutes.
Do I need to prepare?
- No fasting in most centres, though some ask you to avoid a heavy meal beforehand.
- Some centres ask you to take a small enema 1 to 2 hours before to clear the lower rectum.
- Wear comfortable clothing.
- Tell the team if there is any chance of pregnancy.
Will the test be painful?
The test is not painful. It is, understandably, embarrassing — but the imaging team performs these regularly and treats the study with the seriousness and discretion it deserves. The barium paste insertion can feel like pressure; sitting on the commode and being asked to defecate in this setting is unusual but the procedure cannot be done any other way.
After the test, some patients have a slight urge to continue passing barium for a day or two — entirely normal, and the paste passes harmlessly in the stool.
How long do the results take?
A radiologist typically reviews the recording immediately after the test and may share a preliminary impression. The formal report reaches your doctor within 24 to 72 hours.
What treatments may follow an abnormal defecography?
Most findings have treatments
The findings on defecography lead to specific, targeted treatments. Pelvic floor dyssynergia is treated with biofeedback physiotherapy, which is remarkably effective. Rectoceles can be repaired surgically if they are large and trapping stool. Rectal prolapse usually requires surgical correction. Mild findings can often be managed conservatively with dietary and toilet habit changes alone.
Are there risks?
The main considerations are:
- Radiation exposure — the test uses fluoroscopy. Centres minimise dose, but pregnancy must be ruled out before the study.
- Mild leakage of barium for the first day after the test.
- Temporary loose stool as the barium passes.
There are no significant procedural risks beyond these.
What if I am too embarrassed to have this test?
Many patients put off defecography for years for this reason, then are surprised at how matter-of-fact the experience is. The imaging staff are trained in pelvic-floor studies and approach the test with full professionalism. Bringing a partner or family member into the changing area beforehand, having a clear explanation in advance, and asking for any specific accommodations all help. Talking to a continence nurse or pelvic floor physiotherapist before the test can also reduce anxiety.
Conclusion
A defecography is the most direct way to assess what actually happens in the pelvic floor during the act of defecation. For patients with chronic constipation, incomplete emptying, or pelvic floor prolapse, it can be the single most useful investigation — and it routes patients to specific, often highly effective treatments. The test is uncomfortable in concept but generally well tolerated in practice, and the diagnostic yield is high.