Dr Lacy recaps his presentation on treating patients with functional abdominal pain—now called centrally mediated abdominal pain syndrome—from the ACG 2021 Postgraduate Course on October 24, 2021, including diagnosis, testing, and treatments.

Brian Lacy, MD, is a professor of medicine at the Mayo Clinic in Jacksonville, Florida.

TRANSCRIPT:

My name is Brian Lacy. I'm a professor of medicine at the Mayo Clinic in Jacksonville, Florida. I'm speaking from the American College of Gastroenterology meeting in Las Vegas, Nevada. I was honored to be able to give a lecture today on functional abdominal pain, which we now call centrally mediated abdominal pain syndrome, or CAPS.

This problem is more common than we previously thought. Although we don't have great data about the epidemiology, we estimate that the prevalence is about 1% for the general population or about 1 person in a 100. Certainly, for those of us who practice in specialized gastroenterology clinics, it's more common than that.

Who would be the more typical patient with somebody with functional abdominal pain or CAPS? It's more likely to be a woman patient than a man patient, and usually in their late 30s or 40s.

How do we identify these patients? Fortunately, there is a standardized definition, and I tend to use the Rome IV criteria, which defines CAPS, centrally mediated abdominal pain syndrome, as the onset of symptoms at least 6 months ago with symptoms being present for the last 3 months.

These patients are characterized by chronic, near daily abdominal pain that interferes with their life to some degree, meaning their home life or professional life or social life. In contrast to patients with irritable bowel syndrome, it is not relieved or made worse by having a bowel movement. In contrast to patients with functional dyspepsia, it's not always meal related.

I mentioned those 2 disorders of IBS or irritable bowel syndrome and functional dyspepsia, because those are the 2 common causes of chronic abdominal pain that sometimes masquerades as CAPS or functional abdominal pain.

When you evaluate these patients, one common question that comes up is, what are you obligated to do? What testing is necessary? There's no validated algorithm for required tests. It's really very patient-independent.

The start of this is really taking a great history. Do they have near daily abdominal pain? Is it chronic in nature? Is it relieved by having a bowel movement? Is it made worse by eating? To eliminate some of those things on our differential diagnosis list.

Then think about warning signs. Generally in clinic when we see a patient with chronic pain like this, of several years duration, it's unlikely to represent something sinister, but of course, we want to make sure that nothing more serious is going on, or there's not a secondary problem. I ask about unintentional weight loss or unexplained anemia or hematochezia or family history of GI malignancies.

We make sure as we initiate this protocol, this evaluation process, a careful examination is critical. Make sure you look for Carnett's sign or a trapped intercostal nerve

Then coming back to the testing question is really depends on what's been done. If they haven't had recent laboratory tests, that's reasonable. In the appropriate patient, you may need cross-sectional imaging, and in the age-appropriate patient, a colonoscopy would be valuable, but for a younger patient with years of symptoms, you may not need any tests at all. You just need a great history and exam.

How do you treat these patients? That's a critical question. Fortunately, now, we have good data showing that neuromodulators, such as a tricyclic antidepressant, may be useful. An SNRI, a serotonin-norepinephrine reuptake inhibitor, may be useful, and atypical agents such as mirtazapine or Buspar may be useful as well.

As you become more comfortable with seeing these patients and treating these patients, consider augmentation therapy that may mean adding a second agent to the first—maybe using a tricyclic and an SNRI or maybe using SNRI and coupling it with cognitive behavioral therapy.

A key teaching point is don't be overwhelmed by these patients. You have a great opportunity to not only educate them and reassure them, but also to change their lives and improve their symptoms.

Hopefully, this has provided some new information. We look forward to seeing you for other podcasts or other videos on the GI Learning Network.