Brian Lacy, MD, and Baharak Moshiree, MD, on Irritable Bowel Syndrome: Part 1

In this first part of a 2-part podcast on irritable bowel syndrome, Dr Brian Lacy and Dr Baharak Moshiree discuss the difficulties and importance of arriving at a positive diagnosis of IBS.
 

Brian Lacy, MD, is a professor of medicine at the Mayo Clinic in Jacksonville, Florida. Baharak Moshiree, MD, is professor of medicine and director of the motility laboratory in the division of gastroenterology and hepatology at Atrium Health in Charlotte, North Carolina.

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 am absolutely delighted to speaking today to Dr. Baha Moshiree, professor of medicine and director of the motility laboratory in the division of gastroenterology and hepatology at Atrium Health in Charlotte, North Carolina. Our topic today is one that is important for every health care provider, regardless of specialty. That's irritable bowel syndrome.

Baha, thank you for joining this podcast today. Let's begin, simply, to set the stage for our listeners. How common is irritable bowel syndrome, which we'll frequently refer to today as IBS?

Dr. Baharak Moshiree:  Thank you, Brian. I'm really excited to be on this podcast, and it's definitely a topic that's of great interest to me, our patients, and, I know, our gastroenterologists around us. Irritable bowel syndrome is a chronic abdominal pain condition, as we all know. The prevalence in the United States, at least, is about 5%.

We spent a huge amount of health care dollars -- up to 10 billion dollars in the United States -- on pharmaceutical drugs and diagnostic testing to treat our patients who have irritable bowel syndrome. There is also a mental and physical burden on both society, caregivers of patients with IBS, and of course, our patients.

I would say probably during COVID, these diseases and disorders that we used to refer to as irritable bowel syndrome have escalated. This is fantastic to have this right now for our audience.

Dr. Lacy:  Obviously, a common problem with a huge impact to patients, and to the health care system as well. Baha, why a guideline on IBS? Aren't review articles and original research articles, isn't that enough for our health care providers and practitioners?

Dr. Moshiree:  Maybe before I worked on this guideline with you, Brian, [laughs] I may have felt that just reading studies and manuscripts, especially with original papers, was very valuable. But going through the process of this whole GRADE system—which is the grading of recommendations, assessment, development, and evaluation— and this rigorous way that we met monthly, went through all the international studies that have been done — whether it was on the diagnostics or the pharmaceutical drugs — and looked at the study populations, looked at the outcomes, made sure that the study's designs were valid, the statistical findings were valid, and that we picked the most robust studies to make these recommendations that we made.

This is the first guideline that the ACG did on IBS because we had a lot more interventions and drugs that we had available. Other than that, dietary recommendations that we'll talk about, psychotherapies, neuromodulators, etc. It was the most rigorous way of analyzing this. We used the Delphi method where all the experts had to agree on these recommendations. Then, we gave the recommendations a point system on terms of the strength of the recommendations, and then also the level of evidence based on all of the studies that we have. Much better way of making decisions for our GI physicians.

Dr. Lacy:  Great overview. A very strict and rigorous process that allows us to look at this data in a comprehensive manner. In this guideline, there were 25 key questions that were addressed. Let's begin with a number of short questions about the diagnosis of IBS. We'll focus on that first. What is the recommendation about testing for celiac disease in patients with IBS and why?

Dr. Moshiree:  For this celiac diagnosis, the prevalence of celiac is about less than 1% in the United States. In patients specifically with irritable bowel syndrome with diarrhea, after reviewing all of the studies that we had available to us, we found that patients who have IBS-D have 3 times the risk of having celiac sprue.

The symptoms of celiac, patients can be totally asymptomatic, but they can also have other ramifications other than just abdominal pain, diarrhea, and in some patients even constipation. There are neuropsychiatric issues that can happen in celiac.

Infertility is a risk factor in patients with celiac disease, which is very important, obviously, to men and women in the age ranges that IBS occurs, which is in the 20s and 30s. And then also, importantly, the risk of malignancy, which is lymphoma, is important.

After review of the studies, because of this increased risk in patients with IBS, we made the recommendation of at least doing serologic testing, which is fairly noninvasive with the tissue transglutaminase IgA, and then serum IgA testing to make sure they don't have IgA deficiency as a minimum.

It would really impact those patients that could have celiac disease, and then dictate their treatment going forward with the gluten-free diet and others. Upper endoscopy was not necessarily advocated because it is invasive, so small biopsies are not necessarily needed, although that is the gold standard.

We decided that the sensitivity and specificity of serologic testing is good enough for that to be the recommendation.

Dr. Lacy:  Absolutely. One thing that you alluded to, too, is don't forget that some patients may have IBS and celiac disease. They're not, "It's either-or." Sometimes they coexist. Focusing on a bit of a different population too, there's always the concern does somebody have IBS, or do they have IBD, inflammatory bowel disease?

What tests were recommended by the guideline to help distinguish these two disorders?

Dr. Moshiree:  Absolutely. There's a lot of concern for patients. There are commercials on TV about different drugs for inflammatory bowel disease. Usually, the symptoms can be indistinguishable in 40% of patients, so these do overlap. After having 5 years of symptoms of IBS, there is an increased risk of developing or having IBD.

In especially the patients that have the diarrhea-predominant IBS, the recommendations were for stool testing. This is with stool calprotectin and stool lactoferrin. The stool calprotectin had a better sensitivity and specificity. The studies with lactoferrin were less robust; however we recommended both based on the data that we now have available to us.

Then, doing serology testing with CRP was also a recommendation where stool testing is not available. Also, CRP testing is much more accessible to many centers. The testing comes back much quicker than the stool testing, so we also recommended serology testing where that's available.

This really helps because this is, again, inflammatory bowel diseases have a totally different treatment than IBS with diarrhea, specifically. That would also change management quite a bit. We also made a point that alarm symptoms also would dictate testing for inflammatory bowel diseases in a patient that has irritable bowel syndrome.

Taking a really good history is important in terms of rectal bleeding, weight loss, family history of inflammatory bowel disease, is also very important.

Dr. Lacy:  A great teaching pearl for our listeners today for a patient that might possibly have IBS or IBD. That fecal calprotectin that's normal, a normal CRP, and the absence of warning signs is very reassuring that it's not IBD. Baha, we know that many patients develop this post-infection IBS after an enteric infection.

What's the utility of testing for an enteric pathogen in patients with chronic IBS symptoms?

Dr. Moshiree:  Enteric infections, of course any kind of food poisoning, whether it's bacterial, viral, or parasitic, they are common. There are 20,000 cases of parasitic infections in the United States every year. This pertains to giardia, which causes a condition called giardiasis that can affect the small bowel and colon, causing a watery diarrhea.

There's also cryptosporidium. Then, bacterial infections like campylobacter, E. coli, etc., can also occur. Eleven to 14% prevalence of IBS exists in patients after having bacterial infections. These are relatively common. It's called post-infectious irritable bowel syndromes. Of course, with COVID-19, there's also this increased risk of developing symptoms of irritable bowel syndrome.

However, when we reviewed the records, we found that in a patient that has chronic symptoms of diarrhea and abdominal pain, the usefulness of checking for bacterial infection and viral infections diminishes since those are more acute causes of diarrhea.

However, specifically for giardia antigen, if there is that exposure history, for example if they were camping, or swimming in a water system that may have been exposed to giardia, contacts that were sick, or travel abroad, etc., then there is utility in checking a giardia antigen.

The recommendation based on review of the studies was that if there is that exposure history, that giardia antigen, specifically, should be checked for. It's an easy stool test that can be obtained. That would then dictate treatment. That's the only one that could have similar symptoms to chronic diarrhea and IBS-type symptoms.

Dr. Lacy:  Wonderful. Baha, I know you see a lot of patients sent in for second, third, fourth, fifth opinions. I'm sure you see many younger patients with IBS who have had 1 if not 2 colonoscopies. We know the peak for diagnosing IBS patients is late 20s, early 30s.

It's a disease of younger patients, so what's the utility of performing a colonoscopy in younger patients with IBS symptoms without warning signs?

Dr. Moshiree:  Based on several studies, performing a colonoscopy is not helpful, even in assuring a patient that they don't have malignancy. There's a level of concern, of course, when patients have abdominal pain, or symptoms, whether it's alternating diarrhea/constipation, or diarrhea with or without constipation.

Taking a good history, showing that there's a good communication between the patient and the physician, doing a great, thorough physical examination, for example, those are all really helpful in the absence of any alarm symptoms. Of course, alarm symptoms would dictate that the patient would need a colonoscopy. Family history of colon cancer would dictate that.

Also, importantly, the age at which a screening colonoscopy should be done is now decreased to 45 years of age based on the US Task Force findings that younger people are getting colon cancer. So really 45 is, right now, the cut-off age for having a screening colonoscopy, but that's different than for the diagnosis of IBS. For the diagnosis of IBS, doing a colonoscopy does not assure patients, and has not been found to be helpful because there's not increased risk of polyps in patients, and there's not increased risk of colon cancer in patients who have irritable bowel syndrome symptoms.

Dr. Lacy:  Great, thank you. That really helps our listeners. This is a great segue because you talked about a good patient visit. Listening, educating, reassuring, not necessarily just doing test after test. There were two statements in the guideline that focus on the need to make a positive diagnosis for patients with IBS, rather than operating on a diagnosis of exclusion.

Can you comment on why that's so important?

Dr. Moshiree:  There's been multiple studies looking at exclusionary approaches by physicians doing diagnostic testings, whether it's colonoscopy or imaging, versus this positive diagnosis for patients with IBS. Both approaches had the exact same outcome when it was looked at, at 1 “year.

Acceptance of the therapy and its adoption by patients led to a decrease in anxiety. As we all know, anxiety and depression are comorbidities of patients who have irritable bowel syndrome. The confidence that we as providers can bring to a patient by giving this positive diagnosis that...Your diagnosis is irritable bowel syndrome, and this is now my treatment plan,” And really getting the patient to understand their disease process from whether it's pictorials—pictures can be supremely helpful—showing them the brain/gut interaction, and how this has essential and a peripheral component to pain, and that it's important for us to treat both to get a better management plan going forward is very helpful.

Of course, 70% of gastroenterologists, based on this survey, still stated that IBS, for them, is a diagnosis of exclusion. And 80% of the costs in health care that's spent on IBS is driven by testing. Again, there's also this economic burden that overtesting creates. But a lot of that also has to do with the decreased time that physicians or providers have to spend with their patients when they're in clinic.

Literally, an hour ago I saw a patient who agreed that she probably has irritable bowel syndrome. She didn't understand the pathophysiology of the disorder, the fact that the comorbidities she has, which were fibromyalgia and anxiety, could be related. Once she understood everything, it was like 5 years of diagnostic testing were washed away.

Dr. Lacy:  Wow, great teaching points. Another great point to emphasize, as you've already done, is be positive about that diagnosis. Don't say, "Mrs. Jones, you might possibly have IBS." Say, "In my experience, you have IBS. Now, this is what we need to do." Be positive and make that diagnosis confidently.

Baha, before we shift gears to the treatment of IBS, one last question about diagnostic testing. What about the role of anorectal manometry? Aren't anorectal disorders more of an issue in patients with chronic constipation?

Dr. Moshiree:  When we did review the records, this diagnostic guideline was the hardest to grade for our statisticians and our grading team because of lack of data and some of the studies were constipated patients. The others had both patients who had chronic idiopathic constipation and IBS with constipation. It was hard to differentiate the two.

However, after review of the studies that we had available to us at least, patients who have irritable bowel syndrome, 40% of them can have an overlap with dyssynergic defecation.

Of course, we all know that these are disorders that affect women in their 20s and 30s who, most likely, have had pregnancies, whether vaginal or c-section, and specifically, the symptoms of painful evacuation, digital dysimpaction, which are more pelvic-floor disorder symptoms. Then, a long duration of this constipation symptoms all overlapped with dyssynergic defecation in IBS patients.

The most importantly, this can affect outcomes because the patients that were identified as having dyssynergic defecation, and underwent biofeedback therapy, they actually had improvement in even their abdominal bloating and abdominal pain, despite the fact that they had this diagnosis of IBS. That appeared to have an impact, but it could not be graded based on the guidelines.

Dr. Lacy:  Baha, wonderful. We've covered many of the diagnostic questions. Let's take a break. We're going to shift gears, and now let's start thinking about treating IBS.

Join us for our next podcast on IBS, when Dr Baha Moshiree and I will talk about treatment options for these patients with these difficult and persistent symptoms.