Proctography/Defecography

Defecography (also known as proctography) is a diagnostic imaging test where MRI (magnetic resonance imaging) is used to show the function of the pelvic floor during defecation.  Images of the rectum and surrounding organs are recorded during defecation and these images are analyzed by a Radiologist to understand disorders of anorectal function.

At The Ottawa Hospital, this test is carried out in the MRI scanner with the patient lying down on their back with their legs lifted on cushions to simulate a seated position.

Defecography may be indicated for the following reasons;

• Evaluation of rectal outlet obstruction (obstructed defecation) symptoms.
• Suspected conditions such as internal rectal intussusception, enterocele, anismus, rectocele or sigmoidocele.
• To compare pre- and post-surgical repair of rectal outlet obstruction (obstructed defecation).

On the day of your exam, you will be required to take a Fleet enema between 2 to 3 hours before your exam time.  This is required to ensure that the rectum is empty.  You will also be asked to bring an adult diaper with you for use during the exam.  The Fleet enema and adult diaper can be purchased at your local pharmacy.

When you arrive for your MRI exam, you will be asked to change into hospital gowns and put on your adult diaper.  You will then speak with the MRI Technologist, who will once again clear you for MRI safety, and then thoroughly explain the exam to you.

Next, the MRI Technologist will bring you into the MRI exam room and ask you to lie down on the table on your side.  At this point, a Radiologist will enter the room to perform the procedure.

The procedure begins with the Radiologist inserting an enema tube into the rectum.  This is to allow the insertion of water-based gel until there is adequate distention of the rectum, creating the urge to defecate.  During this procedure, one may experience some mild cramping.

Following this procedure, the Radiologist will remove the enema tube, and you will be asked to turn onto your back for the rest of the exam.

You will then be moved into the MRI scanner to begin the exam.  During the exam, imaging will be recorded prior to, during, and after defecation.  These images allow the Radiologist to observe the anatomy and function of the rectum and pelvic floor.

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Last updated on: February 10th, 2025