Brian Lacy, MD, and Satish Rao, MD, on Dyssynergic Defecation

In this first podcast of a 2-part series, Drs Brian Lacy and Satish Rao discuss the challenges of diagnosing dyssynergic defecation and what distinguishes it from chronic constipation.

Brian Lacy, MD, is a professor of medicine at the Mayo Clinic in Jacksonville, Florida. Satish Rao, MD, PhD, is the J. Harold Harrison, MD, Distinguished University Chair in Gastroenterology, founding director of the Digestive Health Center and professor of medicine at Augusta University Medical School in Augusta, Georgia.

TRANSCRIPT:

Dr. Brian Lacy:  Welcome to this Gastroenterology Learning Network podcast.

My name is Brian Lacy. I'm a Professor of Medicine at the Mayo Clinic in Jacksonville, Florida. I'm delighted to be speaking today to Dr. Satish Rao, who carries so many different titles that could probably take most of the podcast.

He is the University Chair in Gastroenterology, the J. Harold Harrison Distinguished University Chair. He is a professor of Medicine, he is the director of the Neurogastroenterology and Motility Center at Augusta University. All you have to do is open up any GI journal, any month, and you'll see a wonderful article from Dr. Satish Rao. We're so pleased to have him here today.

Today, we're going to focus on a topic that's really important for every provider, regardless of specialty. That's the topic of pelvic floor dysfunction.

Dr. Rao, welcome. Pelvic floor dysfunction is such a broad term. How do you define this? How is this different than pelvic floor dyssynergia or dyssynergic defecation, or are all they the same?

Dr. Satish Rao:  Thank you, Brian. Thank you for that very generous introduction. I'm honored to be on this very important educational podcast show. I appreciate this kind invitation.

With regards to this very important question that you brought up, the term pelvic floor dysfunction and the other term, and I always say what is in a name, but I think of the many terms that have been used, this has become a very challenging area.

All of us were describing the same elephant. It's like the 5 blind men and the elephant. Each one had 1 part to it or at least felt was 1 part to it. We struggled with this. Then I was one of the first people who coined this term, dyssynergic defecation. I think this encapsulates the main essence of the problem.

What happens in these folks, unfortunately, is that the act of pooping or defecation has become incoordinated or dyssynergic. Dyssynergic, as you know, is a medical term they use for anything that is not coordinated.

This term very aptly captures the essence of the problem that this incoordinated act is what we are trying to fix. We're trying to make it more smooth, more coordinated, and once you learn that, you get better. It jives with all of those reasons, and hence the correct term would be dyssynergic defecation.

In a more broader sense, the word pelvic floor dysfunction encompasses many other issues, and that is important to recognize as well because pelvic floor serves 3 important functions: the act of evacuation or pooping, urination, and sexual function.

It is a little challenging to use such a broad and compassing word as pelvic floor dysfunction because you really don't know which of those three normal physiological functions are not working.

Dr. Lacy:  I like that explanation for a lot of reasons, and I like the way you explained dyssynergia. For our listeners, the way I explain it is many patients, they get the concept of synergy when things are in sync. Thus, if you use that example and say this is now dyssynergic or things are out of sync, not in coordination, they actually get that.

Yes, for this, we'll keep focusing on dyssynergic defecation. When you start thinking about dyssynergic defecation, how common is that? Is this a rare event, or is this more common than we think?

Dr. Rao:  It is extremely common, Brian. I think 40% or more patients with chronic constipation have this condition. This problem becomes a little challenging because you can't pick it up based on asking people questions or surveys because you need more than symptoms to identify this condition.

Therefore, when people do standard epidemiology studies...You do a study, for example, of headache. You can question people and say, "Well, do you have headache? Yes or no? Do you have it once a week or once a month?" People answer yes and no. The challenge when it comes to dyssynergic defecation is the symptoms of constipation are very common.

It affects between 15 to 20% of the population. It is one facet of constipation where the pooping part has become out of sync. To identify that, you will need to run tests, and therefore it has been very challenging to find out how common it is.

Based on a number of studies now across the world, if we take 100 patients with chronic constipation—that is constipation symptoms persisting for at least 6 months or more— in that group, about 40% of patients will have this condition.

Dr. Lacy:  Great way to put in perspective. I like the way you foreshadowed because we're going to come back to testing in just a little bit. If we think about this problem, which is obviously much more common than many of us initially thought, which population is at risk? Is the misconception that it's just women?

Dr. Rao:  No. Definitely, it is at least 2 times more common in women than in men. At least a third of the patients we see are men with this condition.

Dr. Lacy:  Thinking about some of the common symptoms of constipation. We know infrequent bowel movements. More importantly for our discussion today, maybe straining, incomplete evacuation, and the need to use manual maneuvers, such as perineal support. How accurate are those symptoms at identifying a patient with pelvic floor dyssynergia?

Dr. Rao:  Brian, this is one of the most important questions that you would ever ask me. It really goes to the heart of the problem of, what is constipation? Then what is dyssynergic type of constipation? The challenge has been, over many years, we have not asked the right question from our patients. Our patients also have struggled to define the problem for us.

Fortunately, the Rome scientific criteria have really helped us. Today, we define constipation as the presence of at least 2 out of 6 symptoms. Excessive straining with bowel movement,; hard stools…in a Bristol stool scale, we usually use types 1, 2, 3, which are pebble-like hard stools, are clumped together, and so on. If patients have to use any digital maneuvers to evacuate stools. If patients have a sense of blockage. That is another reason to think constipation. If they have less than 2 bowel movements a week. If a patient has any 2 of these 6 symptoms as present for 3 months out of 6 months, then we would call them as constipated.

Within this broad group of constipated, then there are folks who have dyssynergic defecation. We did a study many years back to try and tease out whether we can identify folks based on symptoms alone. We found that symptoms, unfortunately, were very poor predictors of whether a patient has dyssynergic defecation, or whether they have other types of constipation, such as the irritable bowel syndrome with constipation, or even the slow transit constipation.

We have to rely on other ways, sometimes with our examination skills, or sometimes on testing skills and so on, to help us in a patient who is presenting with these symptoms to truly identify that subgroup of individuals who have this condition.

Dr. Lacy:  Satish, that's a perfect segue to our next question. We recognize clinicians are so busy. Everybody's been asked to do more and more in less and less time. Oftentimes, a digital rectal exam is not performed, for any number of reasons, especially important in a patient with constipation.

How accurate is a good digital rectal exam for pelvic floor dyssynergia? I know you've published on this topic. Could you guide our listeners and how to perform a careful and efficient digital rectal exam?

Dr. Rao:  I didn't know about the timing part of it. The rectal exam, I agree with you, is a very important part of evaluating a patient with suspected dyssynergic defecation.

I recommend we do this after due explanation to the patient, having presence of a chaperone, and also, having proper light and exposure to the perineal region. These are all essential steps in doing a proper exam.

Carefully, one advances the index finger into the rectum. Then we take the other hand, which is the left hand, and place it on the patient's belly. The right index finger is usually inside the rectum. We have the subject push and bear down as if they're pooping.

Recognizing that this is a slightly artificial situation, and patients are lying down. We do this maneuver at least a couple of times to be sure that the patient has understood what the maneuver is and how they're performing.

A normal individual, when they push and bear down, they will increase the intra-abdominal push effort. At the same time, they will relax the anal sphincter muscle. They will gently push the finger out of the rectum. These 3 are normal mechanisms.

If any 2 of these are not present during a rectal examination, then at the bedside, it raises a strong suspicion for dyssynergy defecation. That is how a rectal exam can be helpful. Then you asked another important question, is how useful is this kind of an examination in clinical practice?

We have done that. We've done a prospective study where we took over 200 patients. These patients had a rectal exam performed by an expert. The rectal exam was graded as whether there was dyssynergia or no dyssynergia.

The same patients then went on to have testing that we normally do for identifying patients with dyssynergic defecation. We compared testing against the rectal exam. We found that the specificity and sensitivity of the rectal exam was almost 80 to 85% in identifying patients with dyssynergic defecation.

You can see that this exam can be extremely helpful at the bedside in identifying the problem fairly accurately with a high degree of confidence. In a patient presenting with these symptoms, I would encourage all my colleagues to please consider this form of examination to help identify the patients, and then that can then lead to managing those patients appropriately.

Dr. Lacy:  Satish, what a great description. I think we could all visualize that careful exam, which produces so much relevant information. I want to highlight something you said, too, meaning that whether you're a male provider, female provider, a male patient, female patient, you should always have a chaperone. Thank you for pointing that out.

Let's shift gears again and think a little bit about testing. You've already made the point that symptoms, unfortunately, are not enough. A digital rectal exam can be incredibly useful. What about tests? Are tests required? Do we need just one test? Do we need a combination of tests to make this diagnosis?

Dr. Rao:  Very good question. We generally look at 3 important tests. In the last 10 years or 15 years, I think we've been able to put some expert thought and evidence-based approach to see how useful these tests are in identifying these patients.

The challenge, to some extent, is the act of pooping is a very private event. Then when we try to simulate this act in a laboratory, we bring in other aspects of this testing, which makes it a little challenging for us to literally reproduce the toilet, if you like, or the behavior on the toilet in a lab situation.

That becomes one of the challenges in coming up with a single test or a single maneuver to identify a patient. We therefore use a combination of 3 tests to help us identify the problem. The first and the most important test is anorectal manometry.

What we do is place a very thin flexible probe. That probe has about a dozen very fine sensors on top of it. These are pressure sensors. We place the probe inside the rectum. Then we have the subject perform a number of maneuvers, particularly the push and bearing down maneuver.

We look for pressure changes in the rectum as well as in the anal canal. Patients who have dyssynergic defecation have an abnormal pattern of pooping. We are looking for those patterns to identify. In addition to demonstration of the pattern, we always look for 1 other abnormal test.

In studies of healthy people as well, we have found that up to 15% of healthy people will show this pattern when tested in the laboratory. To have the confidence that we are truly dealing with a patient who has this problem, we need 1 other test.

That is either an abnormal balloon expulsion test. What we do is we place a balloon in the rectum. We fill it up with 50 ml of warm water. Then we have the person sit up on a commode. We give them privacy to poop this balloon. We give them up to 5 minutes.

Typically, most healthy people will pass the balloon in less than a minute. If a patient is taking more than a minute, then it suggests that they have a problem with pooping. Some people with dyssynergia can also expel the balloon.

Therefore, in those instances, we need 1 other test. That is called a defecography, where we put some barium paste in the rectum, have them expel the barium. As they're expelling the barium, we take X-rays. Either standard X-rays or X-rays with MR machine.

That MR defecography will provide corroborating evidence that indeed, the patient has incoordinated defecation or dyssynergic defecation. Symptoms, anorectal manometry, balloon expulsion test, and rarely, defecography, we need to try and come up with a formed diagnosis of this condition.

Dr. Lacy:  Satish, great explanation. We're going to think about this at a little bit of a higher level for some of our expert listeners who may order a lot of high-resolution anorectal manometry or read these studies.

Thinking about dyssynergic defecation. You mentioned some of the patterns are essentially 4 major subtypes, based on a lot of the research you've published. Does identifying some of these specific subtypes, do you think that leads to a change in treatment?

As we talk about treatment in a second, will most of these patients be referred to physical therapy anyways?

Dr. Rao:  Great question. I think the pattern recognition has been very important, first of all, for identifying how a particular individual's pattern differs from the normal pattern. It also provides some insight regarding what is happening in that individual when they are attempting to poop.

The 4 types that we talk about: Type 1 is a pattern where the individual can generate a good push effort, but at the same time, they're completely blocking off or obstructing their anal passage. In the type 2 pattern, that individual is unable to generate a push force, but is paradoxically contracting the anal region.

In the type 3 dyssynergy pattern, the individual can generate a good force, but is not able to relax. I think it's almost like the anal region has frozen, and they are not able to relax. It just is quiet. In type 4 dyssynergia, they cannot generate a push force, and the anal region is also frozen.

The other part of your question was, how does this help us? We've actually tried to look at it, having treated a number of these folks, to see whether these patterns influence the management. I don't think per se they influence the management.

Why we need to understand these types is because it guides management. I'll give you an example. I gave you the first 2 types. Type 1 is where a person has good push, but they're also paradoxically contracting. In that individual, the person knows how to push, but they don't know how to relax. We emphasize a lot more in that individual, about breathing techniques, but also about how to relax the pelvic floor region.

Now, in type 2 dyssynergia, the person is unable to generate a push force, but is paradoxically contracting. In that individual, we will focus on breathing techniques and how to generate a good push effort. At the same time, also teaching them how to coordinate that push effort with relaxation.

These patterns actually help the therapist, particularly, in focusing on those aspects where the patient has a problem. It helps to remedy the underlying mechanistic disturbance. We use that information to focus on those aspects so that we can get it all right. They will all come back to the normal pattern if we are successful with biofeedback therapy. The patterns are there to guide the therapist.

Dr. Lacy:  Wonderful. That's a great explanation. I think it now makes more sense to people who order this and to read this study. I just want to circle back a little bit and when we think about defecography studies, some institutions do the MR defecography, some do a fluoroscopic study. Advantages, disadvantages? Are they basically equal?

Dr. Rao:  Very good question. Let's go back to the original fluoroscopic or the barium defecography. What used to happen here, we would have the subject lie on a bed and then we would inject a barium solution into the rectum.

Then we would have the subject sit up on a specialized commode. Then we would have them push and bear down, and as they're pushing and bearing down, we would continuously take X-rays, which is fluoroscopy.

Regrettably, this test has almost become obsolete for multiple reasons. Number 1 is radiation exposure concerns to the pelvic region. Number 2, the equipment has become antiquated, and also the radiologists who are trained and knowledgeable are fewer and fewer and fewer. Mostly, it has now been replaced by MR defecography.

Now, MR defecography is clearly a superior test to the traditional barium defecography. However, not all labs are equipped to perform the MR defecography in the sitting or the pooping position, because we don't poop in the lying position. We are not able to pick up all the abnormalities that we would like to pick up with this very important test of defecography.

We miss some things, or some things may be misinterpreted, or may not be seen properly. Ideally, if you can do MR defecography in the sitting position, it is really a phenomenal test because it gives us a lot of information.

Here is the important thing. The MR defecography, for example, not only tells us how the rectum and the anal muscles are behaving, properly or improperly, but it also provides the information about surrounding structures. We can look at the bladder. How's the bladder is behaving. We can look at whether a loop of bowel is coming down and getting stuck in the pelvic region, which we call an enterocele. We also can see whether the rectum is bulging in the front and forming a large pocket where poop inadvertently may get caught up, which is called the rectocele. We can also see internal prolapse or even a franked prolapse of the rectum coming out.

There are a number of other dysfunctions affecting the pelvic floor, rectum, bladder, bowel, which we can pick up and those are some real advantages, which may provide additional information to help us both in diagnosis and in managing these patients with dyssynergic defecation and pelvic floor dysfunction.

Dr. Lacy:  A nice reminder to everybody listening in today how MR defecography in the sitting position could be a great test, not just for dyssynergic defecation, but also for this global pelvic floor dysfunction which you spoke of at the beginning.

Thank you, Dr. Rao, for this great discussion. To our listeners, I hope you join us shortly as we continue our talk on dyssynergic defecation in our next GI Learning Network podcast.