EVERYTHING YOU WANTED TO KNOW ABOUT A PROCTOGRAM
By Dr Vikas Shah, Consultant Radiologist
Problems with the pelvic floor are not as widely discussed in the media as cancer or heart disease, but my experience of seeing hundreds of patients a year has shown me that it can be incredibly distressing and disabling. While a proportion of women will suffer from pelvic floor problems due to previous trauma at childbirth, in most cases the cause is unknown. Men can also be affected.
In this first post of three, I will describe what the pelvic floor is, what problems you may suffer from if your pelvic floor fails, and go through one of the main tests of the pelvic floor: a proctogram.
The pelvic floor is made up of muscles and connective tissue, and provides support to the organs in the pelvis. The pelvis is divided into three compartments: anterior (front) containing the bladder, middle containing the vagina and uterus in women, and posterior (back) containing the anal canal and rectum. This image is a side view of the pelvis on MRI, with the various compartments labeled. The small bowel lies in the center of the abdomen, above the pelvis.
When the pelvic floor weakens, the support for these organs also weakens and they can start to lose their shape. Because the muscles do not maintain tone, people often have to strain hard to be able to have a bowel movement.
Other symptoms that may indicate pelvic floor failure include:
● straining a lot but not being to release bowels easily (obstructed defecation)
● a feeling of needing to go again soon after going to the toilet
● a feeling of a bulge at the front (rectocele)
● needing to insert fingers vaginally and press against back wall to help to release bowels
● a lump coming out of the back passage when you go to the toilet (rectal prolapse)
The only way of knowing from the outside what is happening is to do some form of scan, known as a proctogram. Technically, this is a defecating proctogram because the test is a dynamic test, and done with you straining to see what happens to the pelvic floor when you have a bowel movement. The test can be done with either xrays (fluoroscopic) or with MRI. This test is also variously known as a voiding proctogram, evacuation proctogram and a defecogram.
So how do I do these X-ray proctograms? I follow standard practice but exact procedures may vary between practitioners.
To start with, in my practice all female patients take a small volume of barium to drink before the test to show up the small bowel. The small bowel lies in the center of the abdomen but sometimes can drop down into the pelvis and press on the back passage. This is seen more commonly in women, and particularly following a hysterectomy; therefore men don't drink any barium. Just before the test, a barium paste made up of barium liquid mixed with a thickener is put into the back passage and this is what is expelled. The barium paste is also what gives patients the urge to release their bowels for the test. It is difficult (impossible!) to make the paste the same consistency as feces, because everyone has different consistency and hardness/softness feces. We aim to make it to an “average” consistency.
The patient sits on a commode next to the xray machine, and the radiologist (me!) and the radiographer are behind a screen. Xrays are then taken at rest, and then during straining and releasing of the bowels.
This movie clip shows what happens during evacuation (i.e. actually going to the toilet). This is a normal proctogram test. Note that in the movie clip, barium is black in color.
As the patient starts straining, the pelvic floor drops a little bit, the angle between the anal canal and the rectum opens and barium paste comes out of the back passage. These are all normal occurrences during the act of releasing the bowels. The barium drink shows up in the small bowel which is in the upper half of the video, but this doesn’t drop down into the pelvis to cause any problems.
Many patients worry that they won't be able to expel any paste. This doesn't matter for this test; as long as they try, I will get useful information from the xrays about what is happening inside the pelvis. The test is designed to be as natural as possible, so patients can pee at the same time if this is what they do at home. Once the test is finished, patients go straight to the bathroom to get dressed. All of the barium is naturally expelled over the course of a few days, with no harmful effects. Note that no xray dye or contrast is put into the bladder or vagina, and no enema is given before the test.
In my experience, the test fills people with anxiety until they actually have it done; the vast majority of my patients tell me that it really isn't as bad as they feared. There is no denying that it is a difficult test to go through, and trying to release one's bowels in an xray room is challenging, but even coming for the test is an important step in the journey to getting treatment and improving quality of life.
Coming soon will be articles about the main findings on proctogram tests: rectocele, intussusception, rectal and anal prolapse, and anismus.
Dr Vikas Shah
Consultant Radiologist in Leicester, UK