Defecography

What is a defecography?

A defecography is a type of radiological imaging exam done to investigate potential conditions of the pelvic floor, rectum or anus - that is, anatomical anomalies that could cause an issue during defecation. Contrast medium is inserted in an upright ampoule-like device, which will be visible during the X-ray scan.

What does a defecography involve?

You will be sitting on a special, X-ray sensitive chair equipped with a commode. During the examination, the obstetrics and gynaecology specialist will evaluate the contrast medium-filled device expulsion process from the rectum with X-ray scans. That device is used to simulate the natural defecation process. It is crucial that you follow the doctor’s orders when you will be asked to relax or contract your muscles. Thanks to the X-rays, the doctor will be able to assess if there’s any anatomical issues, such as rectal mucosal prolapse, perineal descent or rectoceles.

After the exam, the colour of your stool may change due to the contrast medium being discharged. Defecography is painless and very safe. However, in more rare cases there may be complications such as local inflammation or intestinal perforation if you have other underlying conditions, such as Crohn’s disease or rectocolitis.

What is a defecography for?

This exam is done in case there are other conditions associated with anomalies during defecation. These may include: chronic constipation, bowel incontinence, rectal prolapse or of the surrounding areas or a feeling of incomplete evacuation. Defecography can help determine what causing the issue is.

How can I prepare for a defecography?

You will have to do an enema to free up your rectum before the exam. That way everything will be clearly visible and the doctor will be able to identify any potential problems. If you’re on any kind of medications, you won’t need to stop using them. It is very common to also do a regular X-ray scan while lying down, to look at the overall area before and after the defecography. Everyone can do this exam, except for pregnant women, as the ionising radiations released by the contrast medium could be harmful.

What does it feel like during the procedure?

It is not a painful procedure; you may, however, feel a slight discomfort.

What would a “bad” result mean?

When done correctly, this exam can identify any anatomical issues which could be causing problems during defecation. These could be: insufficient anorectal angle, a slow opening of the anal canal or any alterations in the rectal wall.