Gut Check: Anne Peery, MD, on Diverticulosis

Host Brian Lacy, MD, discusses the diagnosis, treatment, and prevention of diverticular disease with Dr Anne Peery in the latest episode of Gut Check.

Anne Peery, MD, is an associate professor of medicine at the University of North Carolina in Chapel Hill, North Carolina. Brian Lacy, MD, is a professor of medicine at the Mayo Clinic in Jacksonville, Florida.

TRANSCRIPT:

Welcome to Gut Check, a podcast from the gastroenterology learning network. My name is Brian Lacy. I'm a professor of medicine at the Mayo Clinic in Jacksonville, Florida. And I'm absolutely delighted to be speaking today with Dr. Anne Peery, associate professor of medicine at the University of North Carolina in Chapel Hill, North Carolina. Dr. Peery is a nationally recognized expert in a number of different gastrointestinal disorders, including that of diverticular disease, our topic today.

She has authored countless articles and guidelines on the evaluation, diagnosis, and treatment of patients with diverticular disease. She is a sought-after lecturer nationally on this topic and many others. Today we are going to focus on the many aspects of diverticular disease and try to dispel some myths and misconceptions about this common gastrointestinal disorder.

So Dr. Peery, welcome. What a delight to have you here. Let's set the stage for some of our listeners who may not be as familiar with diverticulosis as you are. First of all, how common is this problem?

Dr. Peery: Dr Lacy, thank you for having me today.

So diverticulosis is really common. It's actually the most common finding on colonoscopy. So after the age of 60 about 50% of people in the United States actually have diverticulosis.

Dr Lacy: And why does diverticulosis develop? Can we dispel the myth that this is just simply related to the lack of fiber?

Dr Peery: Okay, so we don't know why diverticula develop. We used to think that a low-fiber diet and constipation caused diverticulosis; we now have evidence that that hypothesis was wrong. So a handful of studies have found no association—no association—between dietary fiber intake, constipation, and risk of diverticulosis.

There is exciting evidence that genetic variants are associated with diverticulosis. So a recent transcriptomic study suggested that tissue remodeling is a primary mechanism for diverticulosis development or formation.

Dr Lacy: So Anne, are some populations at higher risk for diverticulosis? You've already mentioned genetics and maybe that's the root cause, or should we also talk about ethnicity or medication use?

Dr Peery: Yeah, so there are some populations who are at higher risk. I can really only speak to US populations because that's where we really have data. The prevalence of diverticulosis, it increases with age in both men and women of all races and ethnicities. At every age before 80, men are a little more likely to have diverticulosis compared to women. Beyond that, non-Hispanic Black and Asian and Pacific Islander people are less likely to have diverticulosis compared to White individuals. Now, among those non-Hispanic Black individuals and Asian Pacific Islanders who do have diverticulosis, they are more likely, if they have diverticulosis, to have it on the right side, and we don't understand yet what drives these differences.

Dr Lacy: Really very, very interesting.

So you've mentioned how this is certainly much more common as people get older, especially after the age of 60. What's the natural history of diverticulosis? Will most patients develop symptoms or a complication, or do most remain asymptomatic?

Dr Peery: You know, thankfully, most people with diverticulosis will never develop a problem. We really don't think that diverticulosis causes chronic GI symptoms. We do know that a small number of people with diverticulosis will go on to develop diverticulitis or just that acute inflammation in the diverticulum, and an even smaller number will experience diverticular hemorrhage from a ruptured artery in the diverticulum.

Dr Lacy: So let's consider those complications of diverticulosis a little bit more and focus in on diverticulitis. Many of our listeners who are health care providers were probably taught that the classic triad was abdominal pain and fever and an elevated white blood cell count, and that would be enough to make an accurate diagnosis. Is that true, or does everybody require imaging, such as a CT scan?

Dr Peery: Yeah, you know, unfortunately, diverticulitis has a very nonspecific presentation. And several studies have suggested that we're probably only right 50% of the time when we use just a history and exam. There have been really commendable efforts at developing decision tools to make a diagnosis; unfortunately these just weren't accurate enough. So a CT scan can be really useful to confirm an initial diagnosis. That doesn't mean we have to get a CT scan for every episode, but you do need to consider imaging when you've never had imaging or in more severe presentations or in those patients who have ongoing or worsening symptoms. You want to rule out a complication like an abscess or perforation.

Dr Lacy:  So Anne, that's just a perfect segue, thank you. So let's consider that patient with acute diverticulitis and some of those common but nonspecific symptoms you mentioned. What characteristics do you use to distinguish uncomplicated from complicated diverticulitis and tell our listeners how that changes your treatment paradigm.

Dr Peery: Right, so patients with diverticulitis and a complication usually are really quite sick and are presenting to the ER with fever, high white count. I was speaking with a woman yesterday who had a perforation and an emergency Hartmann's and she can't remember even going to the ER. She was just that sick.

Sometimes diverticulitis will be more chronic or smoldering with ongoing inflammation and symptoms. I have seen these patients in clinic and they often present with weeks to months of symptoms and persistent inflammation on imaging. That's a different phenotype, that chronic or smoldering diverticulitis. These patients actually often do respond to a prolonged course of antibiotics or sometimes even will need a surgery.

Dr Lacy: Wow. Wide spectrum of presentations; kind of lets us know that we really need to keep our blinders off for these patients. And so you mentioned antibiotics, and I know that's been a controversial topic for the treatment of diverticulitis. Does everybody need antibiotics for diverticulitis, and if so, which ones?

Dr Peery: Right, so everyone does not need antibiotics based on 4 trials. Guidelines now suggest that we can use an antibiotic-sparing approach in outpatients who are immunocompetent, not frail, who have like a relatively mild symptom burden of less than 5 days, left-sided diverticulitis with no evidence of a complication, access to care, and good social support.

If we are going to use antibiotics, there are a few options. Amoxicillin/clavulanic acid is certainly comparable to using a fluoroquinolone with metronidazole.

Dr Lacy: OK, great. So let's consider you see so many of these patients. And let's take maybe one of your patients who a month ago or 2 months ago had mild uncomplicated diverticulitis and whether or not they needed antibiotics or didn't, and now they are recovered. They come back to see you, kind of for a checkup. What do you tell them about the next episode? Will they get a second episode? Will they get a third episode? And when might that occur?

Dr Peery: Yeah, no this is really useful information for patients. I mean they want to know what can they expect to happen. So after a first episode of diverticulitis, the risk of a second episode is about 20% over 5 years of follow-up. After a second episode of diverticulitis, the risk of re-recurrence just increases. So that risk of a third episode is about 45% or 50% over 5 years of follow -up. And after a third episode of diverticulitis, what I tell my patients is I don't have good estimates, but we suspect that that risk of ongoing recurrences is quite high.

Dr Lacy: Okay, good numbers to know. Maybe for our listeners, think about 20% and about 45%. And so, Anne, this is really helpful, and you may recall that many of us were taught many years ago that if you had a second episode, you needed surgery, or third episode, you definitely needed surgery. When do you refer to a surgeon? Is that kind of predictable after that third episode, or can you really personalize that treatment plan for all your patients?

Dr Peery: Yeah, good question. Our thinking about elective surgery has really changed. We don't worry about the number of episodes anymore. We aren't trying to prevent an emergency surgery with an elective resection. We now know that if a patient is going to develop an abscess or perforation, it's actually usually the first presentation of diverticulitis. So we now counsel our patients that an elective resection, it's an option to reduce the risk of recurrent diverticulitis an potentially even improve their quality of life. It is important if a patient is considering surgery that they understand all the risks of having this resection. They also really need to know that even with a resection there's still a lot of remaining colon and there's still some chance of recurrent diverticulitis after surgery. It's probably 15% over 5 years of follow-up.

Dr Lacy: Yeah, such a great teaching point that you know surgery is a big deal, but it doesn't take the risk to zero for a recurrent episode and it’s important for patients and providers to know that.

So you're sitting in the office with that patient again, and it sounds like this nice patient of yours has a lot of questions, and one of them is, "What can I do to prevent another episode of diverticulitis?” Do you recommend exercise or special diets? I remember one wonderful lady from years ago who was told to take the seeds out of her strawberries. Do we still recommend avoiding seeds and nuts? And what's the evidence to support that?

Dr Peery: Yeah, patients, they really do appreciate advice on what they can do to potentially control this disease. And I have a lot of patients who actually, they blame themselves and what they're eating for causing episodes. So I think counseling is really important. I do advise my patients to eat a healthy balanced diet, but you're right, we don't think it has anything to do with nuts, seeds, popcorn. We don't think that triggers diverticulitis. I advise them to be physically active, to work on maintaining or achieving a healthy body mass index. Regular use of nonsteroidals is associated with an increased risk. So we advise them to avoid those, you know, if it's feasible for them. I get a lot of questions about fibers, supplements, and probiotics. We don't think any of those will reduce the risk of recurrence.

Dr Lacy: That's a great teaching point, especially about probiotics, because so many patients use probiotics for a variety of reasons without much data. And certainly, there's really no data here. So that's great

So, and we haven't really touched on the role of colonoscopy yet. Does everybody need a colonoscopy after an episode of diverticulitis? Is the concern over hidden cancer, hidden  colon cancer causing diverticulitis real or is that unfounded?

Dr Peery: Right, so colon cancer can mimic diverticulitis and the risk of a missed cancer, it's really highest among those who have a diagnosis of complicated diverticulitis or a perforation or an abscess. So multiple guidelines now do recommend that we perform a colonoscopy after recovery from what we thought was an episode of complicated diverticulitis to rule out a missed cancer.

Among those patients who have an initial diagnosis of uncomplicated diverticulitis, we're starting to think that risk of finding a missed cancer is really pretty low. So we should be considering follow-up colonoscopy after uncomplicated diverticulitis if that patient just isn't current with their screening or surveillance or if they've developed alarm symptoms.

Dr Lacy: Okay, wonderfully helpful and maybe that'll cut down on some unnecessary colonoscopies. So Anne, as we start to wind down here, let's shift gears a little bit and focus on one of the other major complications of diverticular disease — that of diverticular bleeding. If a patient has an episode of diverticular bleeding, do they warrant special treatment after that acute episode resolves? For example, do we tell them to avoid all aspirin products and all anti-inflammatory agents? And then if they have an episode, how likely are they to have a second episode, maybe in the next 5 years or so?

Dr Peery: Sure, so recurrent diverticular hemorrhage is really quite common. Unfortunately, the risk of re-hemorrhage is actually higher with older adults. I think it's really important that these patients are educated on what exactly happened, like the mechanism of the bleed. This is an arterial hemorrhage. They need to understand that they need to represent to the ER if they do rebleed.

We do know that stopping anticoagulation after hemorrhage is associated with an increased risk of stroke. So if a patient has an indication for anticoagulation to prevent an ischemic stroke, we should not be stopping these agents. It would be reasonable for these patients to avoid nonaspirin NSAIDs.

Dr Lacy: That's really a great teaching point again, and thank you so much. Clearly, if somebody has risk factors for cardiovascular disease or cerebral vascular disease stopping their agents to treat that could be a really a big mistake. So we need to continue those.

So, Anne, you've given us so much great information on diverticulosis and diverticular disease in general. Any last thoughts for our listeners?

Dr Peery: I appreciate the opportunity to be here today. It's fantastic to share these updates with your listeners. So thank you for having me.

Dr Lacy: Well, great. So again, Anne, thank you so very much for your time and expertise today. To our listeners on Apple and Spotify and other streaming networks. I'm Brian Lacy, a professor of medicine at the Mayo Clinic in of Florida, you have been listening to Gut Check, a podcast from the Gastroenterology Learning Network. Our guest today was Dr. Anne Peery from the University of North Carolina in Chapel Hill. I hope you found this just as enjoyable as I did, and I look forward to having you on future Gut Check podcasts. Stay well.