Defecating proctogram

The defecating proctogram is an imaging study performed by a radiologist in which the mechanics of a patient's defecation are visualized in real time using a fluoroscope.

History

Defecating proctography is a technique first pioneered in 1945 during the second world war. Due to a rash outbreak of whipworm, which is known to cause rectal prolapse, defecating proctography gained popularity during this time. It has since become the gold standard for diagnosis of any of a number of rectal contractility disorders, including anismus.

Since then, however, it has fallen out of favor due to inadequate training in the technique, and it is now only performed at a few select institutions around the country. Many radiology residents affectionately refer to the procedure as the "Def Proc", "Defogram", or "Stool Finale".

Technique

In females, pre-procedural preparation involves smearing a small amount of barium contrast in the vagina with careful avoidance of the rectum. This can often prove to be somewhat challenging in certain body habitus individuals.

The technique itself involves insertion of a caulk gun device into the rectum with subsequent manual infusion of barium paste until there is adequate distension. The patient is then transferred to a portable plastic commode which is situated next to an x-ray camera with recording of the defecation. Positioning of the x-ray camera is of paramount importance as visualization of the buttocks, rectal vault and lower pelvis is mandatory.

More recent techniques involve the use of advanced, cross-sectional imaging modalities such as magnetic resonance imaging. The following video is an example of MRI defecating proctography: [1]. Using MRI for this is considered by many to be an outrageous waste of medical resources.

References:

• Bristol Laparoscopic Surgery, http://www.bristolsurgery.com/article.aspx?articleid=100709
• ASCRS: Pelvic Floor Dysfunction, http://www.fascrs.org/patients/conditions/pelvic_floor_dysfunction/