Michael Smith, MD (Host): Welcome to Pediatrics in Practice, a CME podcast. I'm Dr. Mike, and joining me today is Dr. Sofia Guzman, a Pediatric Gastroenterologist from Children's Mercy. And today we're going to be diving into the important topic of diagnosing and testing GI motility in children. Dr. Guzman, welcome to the show.

Sofia Colon Guzman, MD: Thank you for having me.

Host: So what are the most common motility disorders we see in kids and how do they present differently than adults?

Sofia Colon Guzman, MD: I would say by far the most common is constipation. It's often functional and different from adults. I would say in kids we usually see behavior such as stool withholding, soiling, abdominal pain; compared to the decreased stool frequency that adults might get. After this we see esophageal motility disorders like achalasia or ineffective esophageal motility.

They are rare in children, but I feel like they're often misdiagnosed as reflux. So in kids who are having progressive dysphagia, vomiting, maybe weight loss, that's something we want to think about. I would say usually in adults this might present more like food impactions versus kids might have some trouble verbalizing their symptoms and it might just present as vomiting and refusal of oral intake.

We also deal with some feeding and swallowing disorders like oropharyngeal dysphasia. In kids, this can present as you know, as poor growth, recurrent aspiration maybe, cough or choking with feeds; versus in adult this might present more like isolated dysphasia or odynophagia. And then also not very common, but we do see it in kids is gastroparesis or delayed gastric emptying.

Much less common than in adults, but we are seeing it more commonly in children. And again, because depending on their development, it might be hard for them to verbalize what they're feeling. So common symptoms that we might see are poor weight gain, feeding refusal versus an adult might be able to tell you, you know, I have early satiety.

And then finally just some post-surgical patients that we see might be like after an esophageal atresia repair or maybe after a Hirschprung's disease pull-through procedure. These patients might have motility disorders that we might have to see in our clinic.

Host: When should a general pediatrician consider referring a child for GI motility testing and what are those red flags they should look for?

Sofia Colon Guzman, MD: In general, we want to make sure that if symptoms are persistent and severe enough to impair growth and function, as well as maybe failing the first line therapies that we try to perform in general pediatrics and general GI; then we want to make sure we put in that referral. Things that we want to watch out for are this failure to thrive or weight loss, maybe chronic or worsening vomiting, definitely dysphagia or any type of feeding issues that might cause aspiration or recurrent pneumonias.

And then an important one would be very early onset of constipation in the neonatal period, or inability to pass meconium. Finally like maybe sign suggesting intestinal obstruction. So not only constipation, but if patients have associated bilious emesis or abdominal distension, then these might be some red flags that might prompt you to refer earlier rather than later.

Host: You had kind of touched on this a little bit before and I want to dive into it now with you, how do you approach testing in children who are nonverbal or have some developmental delays where symptom reporting may be limited?

Sofia Colon Guzman, MD: That's a great question. We often rely first on objective markers, right? Like our weight trends, but also on caregiver observations are very important in this population, so, the caregiver reports there's been changes in their feeding behaviors. There are increased frequency of respiratory events or cough or aspiration. And then maybe behavioral indicators of pain that that caregiver might describe are key triggers to evaluate further. For example, children with autism, they might have behavioral changes that might actually be a manifestation of them having GI pain or discomfort. And this just lets us have a lower threshold for instrumental testing, especially when there are higher risks like aspiration or poor oral intake causing weight loss.

And then we want to make sure we get that multidisciplinary team involved earlier rather than later in these patients, and this might include not only your pediatric GI, but we might include speech and language pathology, nutrition, occupational therapy, maybe a GI psychologist to help us elucidate what might be going on.

Host: Takes a team effort in those cases, I bet. Functional GI disorders. How do they play a role in motility issues? And also I'm interested, how do you differentiate between functional and structural causes?

Sofia Colon Guzman, MD: So we like to refer to these functional disorders now as disorders of the gut brain interaction. So you might hear this term used around more commonly, and as you know, they're chronic symptoms. They might cause abdominal pain, altered bowel habits, maybe chronic nausea and vomiting, but they're present in the absence of identifiable structural, or inflammatory causes.

And we use our symptom-based criteria called the Rome IV criteria when there are maybe no red flags that you're observing. So what we want to do is we want a careful history to assess what their presentation might be, but also our objective markers. So what does their growth chart look like?

What do their labs look like? Do they have any signs of anemia or inflammation? And those would be red flags to differentiate an organic disorder from a disorder of a gut brain interaction. And then if symptoms are severe or progressive or certainly accompanied by any of these red flags; then we want to make sure we proceed with additional testing, which usually starts with maybe imaging or an endoscopy, but if needed, we proceed with these different motility testing techniques that we have.

Host: Functional GI disorders, how often do you find them playing a role in motility? Is this common?

Sofia Colon Guzman, MD: It's very common, and I will say the majority of pediatric motility complaints are disorders of the gut brain interaction. So when we do testing, we are less likely to find objective data indicating poor motility of the GI tract. But with these red flag signs, we just sometimes want to make sure to rule it out.

Host: Can you walk us through the key diagnostic tools used in pediatric GI motility testing, like gastric emptying studies, for example, and when each is indicated?

Sofia Colon Guzman, MD: Absolutely. So gastric emptying, let's start with that one, that you brought up. It's a nuclear medicine study that just assesses the rate of emptying of solid or a liquid meal maybe. And we want to get this test when there's been persistent vomiting, maybe severe early satiety and when there are other signs of gastroparesis, or feeding intolerance. The other type of procedure we do are manometry, in which we use motility catheters. And this can be either esophageal manometry, antral duodenal manometry or colonic manometry. And we use catheters that measure the pressure and the peristalsis of these areas of the GI tract. And this lets us assess what the peristalsis is working like. And then, another common one would be anal rectal manometry, where we want to look out for a rectal anal, inhibitory reflux, rule out diseases like Hirschsprungs and achalasia. And then pH impedance is a very useful one for us, when there's recurrent regurgitation, maybe suspicion for pathologic reflux, but the history is unclear or atypical respiratory symptoms.

This test really lets us detect both acid and non-acid reflux and how proximal this reflux is occurring and possibly causing symptoms. And I would say we want to think of this test, especially if patients are maybe being refractory to their antacid therapy.

Host: I find this really fascinating, Dr. Guzman, you know, because children often are not great at laying out symptoms. I know you must rely a lot on the caregivers, the general pediatrician for good history. But because you're faced with a patient who may not be able to explain everything to you, right, do you end up doing multiple diagnostic tests to kind of put it all together? Or are you able, between the caregiver and the general pediatrician, are you able to kind of put together a differential and limit how many of these tools you have to use?

Sofia Colon Guzman, MD: I would say the majority of the time with a good history and a lot of reassurance and education to the family, we can certainly limit these tests, especially the ones that maybe require sedation or are long and uncomfortable studies. So I would say a lot of the time we are able to maybe solve a lot of issues or work things up in least invasive measures. I will say certainly when we start doing a workup, it might require more than one test just to make sure what might be going on. Rarely does one test give you the whole story of what's going on with a patient, but we do try to limit it, especially in this age range, try to avoid sedation and longer procedures.

Host: Speaking of the age range here, what are we talking about with GI motility in pediatric patients? Are we looking at mostly infancy, or are we also dealing with toddlers? And if you're dealing with these different age ranges, what are kind of the common motility issues in the younger kid versus the older kid?

Sofia Colon Guzman, MD: We see all ages from birth to basically early adulthood, older teenagers just because in infancy we see a lot of babies who might have just this chronic refractory constipation with some red flags. Like it happened very early on, or maybe they didn't pass meconium in time.

And we always want to rule out Hirschsprungs disease or less commonly anal achalasia with our anal rectal manometry. In toddlers, I would say a more common one might be feeding difficulties or dysphasia that maybe is not progressing with a general GI follow up and feeding therapy and nutritional therapy.

So we always want to see are we missing something that this child is just not able to eat correctly? And as, as patients get older, we're seeing more eosinophilic esophagitis and this can cause dysmotility in the esophagus. And we see this in all ages really, from toddlers to teenagers. And finally, we do get some patients that are a little older, maybe in their teenage years, that have had chronic constipation, but that we want to rule out did they have a short segment Hirschprungs that just wasn't discovered before.

Are they having any neuromuscular disorders that are causing their gut to just move slower than it's supposed to? And then, certainly new pathologies that come up such as, pediatric intestinal pseudo obstruction, which is pretty rare, but we see it sometimes in patients with abdominal distension, just concern of an obstructive process that's not being seen in imaging. And this we can see in all ages, basically.

Host: I'm interested to know what you're most excited about in terms of emerging technologies or, research developments that, you know, you're like, woo, this is going to be good when it comes to GI motility testing.

Sofia Colon Guzman, MD: So I would say the technique I'm most excited about right now is called EndoFlip, or endoluminal functional lumen imaging probe, where we use impedance planimetry to measure not only the diameter, but the distensibility or compliance of the esophagus while a patient is sedated. Which is a great tool to do in conjunction with an endoscopy, and it's basically a screening tool that we use to assess secondary peristalsis, and especially in the pediatric population where awake motility procedures might be very challenging.

This sedated procedure as a screening tool, really lets us rule out, if this test is normal, your peristalsis is likely normal and we don't have to proceed with more invasive testing. And there's been a lot of research into how we can use this EndoFlip in the pylorus or maybe in the anus. So it's been very exciting to see how this progresses.

Host: So this is being used currently?

Sofia Colon Guzman, MD: It is being used currently. It is mainly used for esophageal motility, and again in conjunction with an endoscopy. So it is sedated procedure, but it's a good screening test for esophageal motility that if normal, it lets us avoid additional more uncomfortable testing.

Host: Dr. Guzman, just to kind of summarize, what would you like the audience to know about GI motility testing?

Sofia Colon Guzman, MD: So first I want to make the emphasis that pediatric motility disorders often look different from adults. So let's say constipation, feeding issues and reflux are more common in children and can have different presentation, compared to adults that can verbalize their symptoms very well. And we want to make sure that we have a lower threshold for referral or testing, given that these symptoms affect patient's growth, their feeding, and really their social life, if they're having symptoms like vomiting or soiling. We should know the red flags for early referral, right? If their growth is faltering, if they're having recurring aspiration or pneumonia, and then worsening vomiting, or any refractory symptom that's not responding to our primary interventions, we want to make sure to refer earlier rather than later.

And then in nonverbal or developmentally delayed children, like we discussed before, watch for objective signs, but also really rely on your caregiver and their expertise and knowledge in their own child, as these kids can often present so differently. And finally, we did discuss this before, but many cases are functional, but we don't want to miss the rare serious ones.

So most motility complaints are going to be disorders of the gut brain interaction, but really structural or neuromuscular causes are more likely to affect growth. So we want to get these identified earlier rather than later.

Host: Dr. Guzman, this was fantastic information. Thank you so much.

Sofia Colon Guzman, MD: Thank you so much for having me.

Host: For more information, go to cmkc.link/cmepodcast. If you enjoyed this podcast, please share it on your social channels and check out the entire podcast library for topics that are of interest to you. This is Pediatrics in Practice, a CME podcast. I'm Dr. Mike. Thanks for listening.