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Defecography, also known as evacuation proctography or dynamic pelvic floor imaging, is a specialized diagnostic test that provides detailed images of the rectum, anal canal, and pelvic floor muscles during the act of defecation. Unlike standard imaging, defecography allows doctors to see how the bowel functions in real time, making it an essential tool for evaluating chronic constipation, rectal prolapse, fecal incontinence, and pelvic floor dysfunction.
This test is particularly valuable when patients experience bowel symptoms that cannot be fully explained by colonoscopy, endoscopy, or routine scans. By visualizing the actual process of stool evacuation, defecography identifies problems such as rectocele, internal intussusception, incomplete emptying, or abnormal pelvic floor motion.
In this guide, we will explain what defecography is, why it is performed, how it works, what the results show, and its benefits and limitations, with a focus on how the procedure is carried out at Alliance Hospital BD.
Defecography, also called evacuation proctography or dynamic rectal imaging, is a diagnostic test that provides real-time images of how the rectum, anal canal, and pelvic floor muscles function during a bowel movement.
Unlike routine scans that capture static images, defecography allows doctors to observe the mechanics of defecation. Patients are asked to sit on a specialized commode while contrast material (paste or gel) is introduced into the rectum to simulate stool. X-ray or MRI images are then taken while the patient attempts to pass the material.
Defecography is especially useful for detecting bowel disorders that cannot be easily identified through colonoscopy, endoscopy, or routine pelvic imaging.
Doctors recommend defecography when patients present with chronic or unexplained bowel symptoms, particularly when other tests do not reveal the cause.
Common reasons for performing defecography include:
Chronic constipation with incomplete evacuation
Fecal incontinence or accidental leakage of stool
Rectal prolapse (rectum slipping out of its normal position)
Rectocele (rectum bulging into the vagina in women)
Intussusception (rectal walls folding into themselves)
Pelvic floor dysfunction (impaired muscle coordination)
By visualizing bowel function during defecation, doctors can distinguish between structural and functional problems—helping them select the most effective treatment.
Defecography is a safe, minimally invasive test that usually takes 30–45 minutes.
Step 1 – Preparation
A mild enema may be given to clear the rectum.
Patients are asked to wear a gown and sit on a specialized commode within the imaging suite.
Step 2 – Insertion of Contrast Material
A thick paste or gel (barium for X-ray or contrast gel for MRI) is gently inserted into the rectum to mimic stool.
In some cases, contrast may also be placed in the vagina or bladder to evaluate pelvic organ support.
Step 3 – Imaging Process
The patient is asked to squeeze, relax, and then push as if having a bowel movement.
Images are taken during rest, straining, and evacuation.
X-ray defecography uses fluoroscopy, while MRI defecography captures high-resolution images of soft tissues.
Step 4 – Post-Test
The paste is expelled during the test.
Patients can return to normal activities immediately afterward.
Defecography provides detailed insights into both anatomy and function of the anorectal region.
The test can reveal:
Rectocele – Outpouching of the rectal wall, often into the vagina.
Rectal prolapse – Rectum sliding downward or outward.
Intussusception – Rectal wall folding inward.
Incomplete evacuation – Difficulty emptying stool fully.
Pelvic floor dyssynergia – Muscles failing to relax or contracting incorrectly during defecation.
Enterocele – Small intestine pushing into the rectum or vagina.
By combining these findings with other tests such as anorectal manometry and balloon expulsion tests, doctors can confirm the underlying cause of symptoms.
Real-time evaluation – Shows dynamic bowel function during defecation.
Detects hidden disorders – Identifies prolapse, rectocele, and pelvic floor dysfunction not visible on colonoscopy.
Guides treatment – Helps surgeons plan corrective procedures or recommend pelvic floor therapy.
Non-surgical – Minimally invasive with no major risks.
Radiation exposure (for X-ray defecography) – though minimal, MRI defecography avoids this risk.
Patient discomfort – Some may find the process of expelling contrast paste embarrassing.
Not a stand-alone test – Usually combined with manometry, ultrasound, or colon transit studies for complete evaluation.
At Alliance Hospital BD, we provide advanced diagnostic imaging for patients with colorectal disorders, including high-resolution MRI defecography and X-ray fluoroscopic defecography.
Our specialized colorectal diagnostic program includes:
Expert gastroenterologists and colorectal surgeons for interpretation
State-of-the-art imaging equipment for detailed visualization
Comprehensive testing (manometry, balloon expulsion, ultrasound) for accurate diagnosis
Patient-centered care to minimize discomfort and anxiety
With our multidisciplinary approach, we ensure that patients receive accurate diagnosis, effective treatment recommendations, and long-term support for managing colorectal conditions.
Defecography is a valuable imaging tool that helps diagnose bowel disorders by showing how the rectum and pelvic floor function during defecation. It is particularly useful for identifying rectocele, rectal prolapse, intussusception, and pelvic floor dysfunction.
While it may feel unusual, the test is safe, quick, and provides essential information for planning the right treatment—whether that involves pelvic floor therapy, surgery, or lifestyle changes. At Alliance Hospital BD, patients have access to advanced defecography services with expert medical care, ensuring accurate diagnosis and better outcomes.
