Constipation — Breast Cancer Treatment Side Effects
In this podcast on constipation, Dr. Chey discusses risk factors for constipation, how to manage constipation, as well as his favorite constipation joke. Listen to the podcast to hear him explain:
why he recommends an integrated, holistic approach to managing constipation
why patients need to overcome any embarrassment they have about constipation and be their own advocate for treatment
the steps he recommends when treating constipation
William Chey, MD, is professor of internal medicine and professor of nutrition at the University of Michigan, where he leads the Functional Gastrointestinal Disorders Research Group. His research interests include diagnosis and treatment of irritable bowel syndrome, constipation, fecal incontinence, gastroesophageal reflux disease, and H. pylori infection. During his 30 years of treating people with constipation, Dr. Chey has written more than 300 manuscripts, reviews, and book chapters. He received his medical degree from Emory University and completed a fellowship in gastroenterology at the University of Michigan.
— Last updated on June 29, 2022, 2:49 PM
Jamie DePolo: Hello, everyone, I’m Jamie DePolo, senior editor at Breastcancer.org. Our podcast guest today is Dr. William Chey, professor of internal medicine and professor of nutrition at the University of Michigan, where he leads the Functional Gastrointestinal Disorders Research Group. His research interests include diagnosis and treatment of irritable bowel syndrome, constipation, fecal incontinence, gastroesophageal reflux disease, and H. pylori infection. Dr. Chey has written more than 300 manuscripts, reviews, and book chapters. He received his medical degree from Emory University and completed a fellowship in gastroenterology at the University of Michigan.
Today, Dr. Chey joins us to talk about constipation and ways to manage it. Dr. Chey, welcome to the podcast.
William Chey: Thanks very much Jamie. Thanks for having me.
Jamie DePolo: We are so thrilled you’re here. This is an ongoing topic on our discussion boards. A lot of people experience constipation, and, in fact, one of our discussion board members called constipation the nemesis of cancer patients. So let’s start with me asking you why opioids, chemotherapy, so many of the targeted therapy medicines… why is constipation such a common side effect?
William Chey: Yeah, it really is a common side effect, not just for cancer patients but for just people in general. Realize that somewhere in the order of 12–14% of the U.S. population reports problems with constipation, so anywhere between 1 in 7 and 1 in 10 just garden variety individuals. And certainly when you get into a setting where your diet’s changed, you’re inactive, you’re on medications that can affect the contractility of the colon, the nerve function in the wall of the gut, the immune system in the gut, the microbiome in the gut, it shouldn’t come as a surprise that constipation is a significant side effect for many cancer patients whether they’re on chemotherapy or not.
Jamie DePolo: It’s all those things together combined that cause it.
William Chey: Yeah, unfortunately we don’t really have a way right now to parse patients on the basis of those different mechanistic explanations for their symptoms, and so it can be any combination of one or more of those things. Another thing that I didn’t even mention that’s really important and really under-recognized is pelvic floor dysfunction. So the inability to be able to coordinate the muscles in the lower part of the colon and the pelvic floor to be able to normally evacuate stool from the rectum, that’s another explanation for problems with constipation. It’s particularly relevant because we’re just learning that those reflexes become abnormal in people taking opioids.
Jamie DePolo: Oh, wow.
William Chey: Yeah, it’s literally brand new research that we’ll be presenting at our national meeting in May of 2019.
Jamie DePolo: A lot of women have said they have pelvic floor dysfunction to start with, whether they’ve been diagnosed with anything or not or are taking medications or not, so if you add that on top of medications as you said, it’s going to make the problem even worse.
William Chey: That’s right, that’s right.
Jamie DePolo: I had no idea that constipation was that common in society as a whole.
William Chey: It is. It’s something that people, I think, are quite embarrassed to talk about, and for that reason, it really is a silent epidemic. The other thing that’s interesting is that constipation becomes more prevalent as one gets older, and given the fact that our population is rapidly aging — think about what’s happening with the baby boomers that are all coming into retirement age now — constipation is going to be a real growth industry whether we like it or not. I always say that two big conditions that we’re going to be seeing a lot more of, things that patients won’t necessarily volunteer to talk about, but nonetheless, are going to be constipation and fecal incontinence.
Jamie DePolo: Why is constipation a problem as you get older? Is it just loss of muscle tone, or is there something else?
William Chey: Again, it probably is a combination of different things. So think about this: As we get older, we become less physically active, and we know that physical activity correlates to how frequently you move your bowels. In addition, the function of the GI tract… if you think about it as a long muscle, it probably makes sense that, particularly for people that are constipated through the course of their life, that there may be progressive damage that goes on that leads to more severe problems or unmasks problems that were actually there to a subclinical degree — a degree which was not appreciated by the patient, but then finally gets to a point where it becomes clinically apparent or more clear, where the patient feels as if they’re constipated. And then the last thing is what we alluded to in the cancer patients, is medication in general. The number of medications an individual is taking is linearly related to their age. As we get older, everybody’s taking more supplements, more over-the-counter medications, more prescription medications, all of which can lead to constipation in susceptible individuals.
Jamie DePolo: At least for breast cancer, getting older is a risk factor for being diagnosed. I am assuming that for most cancers that is the case, too, so again aging increases that risk as well.
William Chey: Certainly for the most common cancers — maybe not so much lung cancer — but certainly colon cancer, breast cancer, prostate cancer, that’s clearly true.
Jamie DePolo: Besides pain, feeling uncomfortable, all the physical things you feel when you’re constipated, can constipation cause any long-term problems for a person? If you’re constipated and you don’t really treat it but you just handle it, are you setting yourself up for future problems?
William Chey: We really don’t know that. We don’t have great longitudinal studies that follow patients for many years at a time. You can imagine how hard that would be to do. But nonetheless I can tell you that I’ve been doing this for almost 30 years, so I’ve been following some patients for that long a period of time and some patients with constipation for that long a period of time. I can tell you that my own hypothesis is that progressive periods where the colon is stretched with what we call fecal loading — as a person becomes more and more constipated, followed by episodes of purging, where people move their bowels, sometimes once, sometimes repeatedly. In fact, it’s interesting that a lot of patients with constipation will say that they don’t move their bowels for several days and then they have diarrhea. It’s not really diarrhea. What it is is that the pressure has gotten high enough in the colon to where, literally, stuff comes out forcefully. It’s really a consequence of the constipation, not true diarrhea, and that’s very confusing I think to patients, and, unfortunately, it’s confusing to many doctors.
So for example, if you go in complaining of more frequent loose stools, it’s not uncommon for a physician to prescribe Imodium, or loperamide, to slow you down. Well, guess what? If your problem is what I described, you just threw gas on a fire.
So there are all these things that need to be taken into consideration, but to close the circle on your question, I think that when people go through repeated episodes of loading the colon and stretching it out, that over time, that leads to irreversible damage. Do you get a buildup of toxins? I don’t think so. Do you get an increased risk of colon cancer? No, there’s no conclusive evidence for that either. But it is possible that if you leave constipation untreated it could progress over time and actually leave you in a pretty bad place.
Jamie DePolo: You brought up that doctors may not know what to do. I think, judging from the discussion on our boards, people think their oncologist, because this is such a common side effect, to be able to treat and help manage constipation. That’s not really the oncologist’s area of expertise. So when would you recommend someone see a gastroenterologist? Is there another doctor that someone should see first? What would you recommend as far as the progression?
William Chey: Clearly it will depend on a person’s individual situation. There will be some oncologists who would be very comfortable treating constipation. Some oncologists won’t be as comfortable. The physician and the patient have to have a solid relationship in which the patient feels comfortable exchanging that information. That would be the first bit of advice I’d say, is that an oncologist is not necessarily going to be thinking about whether a patient with cancer has developed diarrhea or constipation. I think diarrhea maybe more so, because that can certainly be very debilitating for some patients. But constipation may or may not be addressed by the oncology team.
So I think the patient has to feel comfortable talking about that with their doctor. And by the way, the doctor isn’t embarrassed about it, it’s the patient that’s embarrassed about it. Patients need to get over that embarrassment and engage with their oncologist. Typically what’s going to probably happen is they’re going to recommend fiber and stool softeners or an over-the-counter laxative. If those things don’t work, it’s time to see either your primary care physician or a gastroenterologist. Certainly, if you’ve tried multiple over-the-counter remedies and/or prescription remedies, it’s time to see a gastroenterologist, for sure.
Jamie DePolo: You just got into a little bit of this, but what everybody really wants to know from this podcast is, how should we manage constipation? You said there are a lot of medicines. People talk about supplements, people talk about fiber or prunes, dried fruit, fasting diets, so if you could talk about each category and what you would recommend. Is there a progression to this? What do you recommend?
William Chey: There is a progression. How long have you got?
Jamie DePolo: [laughs] As long as we need, because I think this is really going to be helpful to people.
William Chey: I’ll try to lead you through this. I, over the years, developed an integrative approach. In other words, I don’t view constipation as only being most appropriately treated with medications. I think there are lots of different options, as you allude to.
First and foremost is if you’re able to be physically active, those individuals who are physically active move their bowels more frequently than those individuals who are sedentary. Exercise, even if it’s walking for variable amounts of time several times per week even if not every day, is good. So exercise is now part of my prescription for every patient that’s able to engage in exercise.
People talk a lot about drinking enough fluids. I think the take-home message for that is, if you’re drinking more than a liter and a half of fluid per day, you’re drinking plenty of fluid, and drinking more than that isn’t going to help. Now, on the other hand, if you’re in a job that’s physically active, that increases your loss of water through the course of the day, and you’re not paying attention to how much fluid you’re drinking — let’s say for the sake of argument that you’re drinking less than a liter of fluid per day — it’d be a good idea to make a conscious effort to drink enough water through the course of the day. Remember, particularly if you’re in a physically active job, you’re going to be losing a lot of fluid through the course of the day, and it’s going to be important to replace that. Studies show that unless you’re in the lowest quartile of people in terms of consuming fluid each day, it doesn’t matter how much you drink. So you’d have to be really drinking very little for it to affect or cause constipation. But if you fit into that category, it’s important to step up the fluid intake.
Jamie DePolo: I don’t mean to interrupt, but I do want to ask: When you say fluid, do you mean specifically water? Because some folks are going to say, I could drink diet pop, I could drink coffee, I drink 2 liters of coffee a day, does that count?
William Chey: No, that’s a really good point. Unfortunately, we do see patients like that. You’re absolutely right. I’ll say to a patient, how much fluid do you drink during the course of the day? I’ll get an answer back like, “about 12 cups,” which is always a clue for, “12 cups of what?” It’s amazing how much coffee or soda a lot of people drink. I would say that the good news about coffee is it’s a stimulant to help people to go to the bathroom. The bad news about coffee is that it contains caffeine, which is a diuretic, which will make you urinate and lose more water. So coffee or caffeinated beverages of any kind would not be the best choice if you want to stay adequately hydrated. Thanks for pointing that out. It’s a very important point.
I think diet also merits some discussion. There certainly are foods that one could eat that can help you to be more regular, some of which you alluded to. So for example, there are now several studies showing that individuals that eat prunes, probably 4 to 6 per day, move their bowels more often than individuals that don’t eat prunes. So prunes are a good natural laxative. Dried apricots are also a very good natural laxative. They both contain a nonabsorbable sugar with laxative properties called sorbitol. The good news about sorbitol is, it’s a natural laxative. The bad news about sorbitol is that, for some people, it can cause a lot of gas and bloating. So what people just have to realize is that if they start on dried apricots or prunes, if they develop a lot of gas and bloating, it’s because of those fruits, ok?
Jamie DePolo: Has anyone done any studies on dried mango? Because I’ve find that to have similar properties myself.
William Chey: Mango contains a lot of fiber, and a lot of sugar as well. I haven’t seen any studies with mango, nor have I made that observation myself, but that’s an interesting thing to note. I’ll take that back and think about that a little bit.
Jamie DePolo: To me, they taster better than prunes and/or apricots.
William Chey: Yeah, the thing that you and your audience may not know is that probably the next best thing to prunes and apricots is kiwi.
Jamie DePolo: Interesting. I did not know that.
William Chey: Yeah. Kiwi actually has laxative properties. There are now several randomized, controlled trials from Asia showing potential benefits for mild constipation in individuals that eat two peeled kiwis per day. We’re actually just finishing up a randomized, controlled trial, the first one in the United States, comparing kiwi fruit to prunes to fiber supplements with psyllium, or Metamucil. So we’ll be done with that study probably within the next 2 or 3 months, and we’ll be presenting that data probably the end of this year or early next year. So stay tuned. We’ll have data from a scientifically rigorous randomized, controlled trial from the United States later this year.
Jamie DePolo: We’ll definitely look for that. I’m sorry, I interrupted you again.
William Chey: No problem. As I said, there’s a lot of different options. Over-the-counter medications: the ones that probably offer the best efficacy with an acceptable safety profile are osmotic laxatives. Those are things like polyethylene glycol, or Miralax, which people may be familiar with. Similarly, magnesium salts, like milk of magnesia, or magnesium oxide, is also very a gentle, natural laxative, and is actually one of my go-to over-the-counter laxatives. So [polyethylene glycol] and magnesium are two of my very favorites, particularly in patients that have mild-to-moderate constipation.
Stimulant laxatives can be very good, particularly for as-needed use. Those would be things like bisacodyl, which is Dulcolax, or senna, which is Senokot, and many other senna-based laxatives. For example, another thing that people don’t realize is laxative tea, which can be very useful for some people, will contain some combination of senna; caspera; rhubarb, which is also a natural laxative; and…what’s the last one? I think that it’s actually... oh, aloe. Aloe is also a stimulant laxative. If you look at the labeling on a laxative tea, you’ll typically see that, either senna, caspera, aloe, or rhubarb. And those are all natural laxatives.
The stool softeners, people talk about a lot, and I guess for really mild constipation maybe that’d be useful, but certainly if you’re having more regular constipation, stool softeners are kind of useless. They don’t really work very well.
And then fiber supplements, of course. Probably the best data for fiber supplements is with soluble, gel-forming fiber, like psyllium, or Metamucil. But there are lots of other fiber supplements, and an individual can try one or more of them and see what works best for them. Not the same thing is going to work for every patient with constipation. As I mentioned earlier, it’s a heterogeneous disorder, and so the solutions vary from person to person.
The last thing I’ll talk about briefly is prescription medications. The good news is that in the last 10 years, we’ve really seen an increase in the options that are available for patients. There are drugs that increase intestinal secretion and improve constipation in that way. So drugs like lubiprostone, or Amitiza; linaclotide, or Linzess; plecanatide, or Trulance; and then finally a brand new one that just got approved this year, which is prucalopride, and that will be available commercially probably in the April or early May timeframe, in the United States.
Jamie DePolo: What would be the progression if somebody starts having mild constipation? My assumption is that they can try some things on their own, maybe try some high-fiber foods, maybe a laxative tea. And then, if things aren’t moving, so to speak, then they talk to their doctor and then do they consider other sorts of medicines?
William Chey: The first thing to do is to try to become more physically active and utilize the dietary advice that I gave you. That would be the first thing I would recommend. And then if those things don’t work, stepping up to the OTC medications that I outlined. But certainly, if you’ve tried one or more over-the-counter medications and it doesn’t work, it’s time to see a doctor. Also, if you have so-called warning signs or alarm features — unintended weight loss, gastrointestinal bleeding, or if you developed these symptoms new, after the age of 50 — then you need to see a doctor.
Jamie DePolo: Do you have any concerns about people diagnosed with cancer using Miralax? Some people on the discussion board have said their doctors told them not to use it. Or is that only if people have kidney problems as well?
William Chey: Actually, kidney problems aren’t a contraindication for the use of Miralax, or polyethylene glycol. It is for magnesium though. So, for example, if you had chronic renal dysfunction, chronic kidney disease, you would not want to use daily magnesium because it could accumulate. It’s renally excreted. But you know, polyethylene glycol is very minimally absorbed. Most of it does not get absorbed into the body, it just passes out in the stool, in fact that’s how it works to help draw water into the lumen of the bowel and help with constipation. Polyethylene glycol is labeled for short-term use, which is probably the reason for the concern on the part of physicians, but I can tell you that for those of us who do this for a living and have been doing it for a long time, we use polyethylene glycol all the time chronically. So I would have no concerns about treating a patient, particularly a cancer patient, with long-term polyethylene glycol.
Jamie DePolo: What about fasting? Some people have told me that intermittent fasting, fasting for specific times, has helped them.
William Chey: Yeah, I don’t know much about that. I’m not sure I can really comment on the fasting thing. What I hear more often is colon cleansing or purges. That I hear about, but I’ve not heard the bit about fasting. Now, in terms of colon cleanses and purges, I think there’s no evidence of efficacy that that’s beneficial, and, in fact, continuously or repeatedly disrupting your gut microbiome — particularly if it’s a healthy gut microbiome — is probably a bad idea. So I would discourage people to do that.
Now that being said, I have a whole host of patients with very severe constipation where I have them do intermittent purges. So there’s a difference between somebody that is going to progressively accumulate stool and stretch the colon out, as I alluded to earlier, and I want to prevent that from happening, and a person that’s either otherwise healthy or has very mild symptoms, in which case I don’t see value based on the evidence as it exists right now, to subjecting them to cleanses or purges.
Jamie DePolo: Now, what about the Squatty Potty®? For anyone that doesn’t know, that’s a little stool that goes around the toilet and you put your feet up so you’re in a “more natural” position.
William Chey: Yeah, it really does put you in a more natural position. It’s been long said — and kudos to the people that developed Squatty Potty®. They figured this out. For many years we’ve talked about the fact that American toilets, specifically, are too high. So because they’re too high, they actually put people into a position when they’re trying to move their bowels that’s unnatural. If you think about ancient man, when they moved their bowels they didn’t move their bowels standing up or even in a semi-erect position. They moved their bowels in a squatting position. And the reason for that is because the angles created by the musculature in the lower part of the pelvis straighten out more in that squatting position. So therefore, the Squatty Potty®, by simply elevating your knees and your feet, puts you in a more physiologic position to be able to fully evacuate stool from the rectum. So for some people, it can be very, very helpful.
Jamie DePolo: You talked about a lot of things. I know you talked a little about order, but if there were the top three things you would recommend to somebody who comes to you, I’ve been diagnosed with cancer, I’m in treatment, I have really severe constipation, what would you recommend?
William Chey: First, don’t be afraid to talk to your physician about it, and try to find some solutions. So you may even talk to your physician about it the initial time, be told to try some other stuff, and then come back in and have the doc not even ask you about it. You’re going to have to be your own advocate on this. With a gastroenterologist, that’s one thing. We’re used to dealing with this. We’re interested in dealing with this. We’re going to follow up with you specifically about this. But I think for oncologists and primary care physicians, who have a whole host of other things that are very important for them to deal with, this is not necessarily going to bubble up as something really important for them to address during their visit with you. So you have to advocate for yourself on this.
Second thing is, again, be aware of the sort of holistic approach that I outlined and not just focus on only medications. I mean medications are important, but taking that more integrative approach is more likely to provide you with a solution that solves your problem.
And the third thing is that if things aren’t getting better, you really do need to see a gastroenterologist.
Jamie DePolo: Finally, because our discussion board members love puns on this topic — in fact there is a whole post with jokes about constipation — I need to ask you, what’s the best constipation joke you’ve heard?
William Chey: I hope this isn’t already on the board! We’ll see. I didn’t take a look at it beforehand, but… have you seen the new movie about constipation?
Jamie DePolo: No.
William Chey: Not surprising. It hasn’t come out yet.
Jamie DePolo: [laughs] That’s pretty good! When the podcast goes live, we’ll have people vote on how amusing they found it. Thank you so much, Dr. Chey. This has been hugely helpful. We really appreciate your time.
William Chey: My pleasure. I hope that it does provide some help and relief for people that are suffering with constipation.