Gastroenterologists debunk 12 myths about indigestion and gut health

• Gastroenterologists Dr. Fola May and Dr. Austin Chiang debunk 12 myths about indigestion.
• They explain how spicy food doesn't cause ulcers and why you don't need to poop every day.
• They also talk about probiotics and why they might not be the cure-all you think it is.

Following is a transcript of the video.

Austin Chiang: "Your stomach shrinks if you eat less." Is that true?

Fola May: Myth!

May: "Jumping or exercising after eating will give you an appendicitis."

Chiang: What? I have never heard of this. I'm tossing that one out.

Chiang: Ooh. So, "You need to wait 30 minutes to swim after eating."

May: I caught myself almost saying it to my own children the other day, and then broke out into laughter, because it's an absolute myth.

Chiang: Hi, I'm Austin Chiang. I'm an assistant professor of medicine at Jefferson Health in Philadelphia, and I've been practicing as a gastroenterologist since 2017.

May: My name is Fola May. I'm an assistant professor of medicine at UCLA Health. I'm a general gastroenterologist and have been practicing gastroenterology for the last six years. I love this field because it allows us to optimize people's digestive health, and we get to prevent important cancers like colorectal cancer.

Chiang: And today we'll be debunking myths about indigestion.

Chiang: "It takes years to digest gum."

May: This is an absolute myth. And I remember this as a child, hearing that it takes seven years to digest your gum. The reality is that everything you eat, going in one end, is going to come out the other. The slight truth of the myth is that gum is insoluble. So we don't have the enzymes to break down gum like we do other foods. But it doesn't stay in your stomach for seven years. Just like everything else you eat, it gets emptied from the stomach usually within 30 and 90 minutes, and it comes out in your stool.

Chiang: "Smelly farts always means something is wrong." I don't know, Fola. Is there such a thing as a good-smelling fart?

May: I get this one a lot from my patients. So, everyone thinks that if your farts smell really bad, then there must be something wrong with the digestive tract. And it's not true! Some of the most healthy foods that we eat, like fiber, broccoli, asparagus, cause the smelliest farts. I will say, though, that it is important to pay attention to whether there are other symptoms, particularly people who have lactose intolerance, which means that they don't have the enzymes to digest milk products. And if you've noticed smelly farts over and over again after eating milk products or after having products like gluten frequently, then it's probably worth looking into whether you have a food intolerance or a food allergy. The other symptoms to keep an eye out for are severe abdominal pain with your smelly farts, loose stools or diarrhea, fevers. This can indicate an abdominal infection.

Chiang: "You should be pooping every day."

May: So, this is another unfortunate misconception that human beings have. It can be normal to have a bowel movement up to three times a day, and there are actually people who are normal who have bowel movements every three days, and anywhere in there in between can be normal. What I typically will tell my patients is that the most concerning thing is if you are having infrequent stools that are causing constipation-like symptoms. Straining a lot when they're on the toilet bowl, have developed blood in their stools when they have a bowel movement. And that's generally when we would prescribe a medication to help you have more frequent, yet gentle bowel movements.

Chiang: The reason why it's important to sometimes get this checked out by a professional is because there are a lot of different causes for infrequent stools and constipations.

May: And then there's the other end of the spectrum. Some people have what we call inflammatory bowel diseases. These are conditions that cause frequent stools but also blood in the stools, severe abdominal pain, and bloating, weight loss, fatigue, other manifestations throughout the body. And that's concerning. So I usually like to tell people that it's not the number of the bowel movements you're having, it's whether or not there are any of these concerning symptoms.

May: Myth or fact? "Only spicy foods cause ulcers."

Chiang: If this were true, I'd be very sad, because I love spicy food and I eat spicy food all the time. Spicy food does not cause ulcers, but that doesn't mean that spicy food doesn't cause pain. What does cause ulcers can be a bacteria called H. pylori that can live under the surface of the lining of the stomach. And this can cause ulcers, as well as certain medications, like NSAIDs, which are basically those over-the-counter pain medications like Motrin, Advil. We want to be careful when we're taking medications like that.

Stress typically does not cause ulcers, although it may make existing ulcers worse. There are certain conditions that are called stress ulcers, but this really applies to people who are very, very sick, like, hospitalized sick, and not the typical type of stress that we think of when we're stressed out.

May: I think that is a common myth though, Austin, right? I mean, you hear people say all the time, "I'm so stressed I'm going to get an ulcer." When I was younger, I would just listen to that statement. And now I kind of want to interrupt and say, "No, actually, that's not how it works."

Chiang: Exactly. But it doesn't mean that stress doesn't trigger, like, belly pain, because, you know, stress can certainly exacerbate and worsen those types of symptoms.

May: Absolutely. Absolutely.

Chiang: But yeah, in and of itself, it's not going to cause an ulcer to just form out of nowhere.

May: Thank goodness, right?

Chiang: Yeah. We'd be seeing a lot more ulcers then.

Chiang: "Your stomach shrinks if you eat less." Is that true?

May: Myth! This is part of what people think they can do to control their weight. There's this misconception that if you eat less, your stomach will become smaller and then you won't need as much food to survive and live your daily life. Unfortunately, it is very false. The size of the adult stomach stays approximately that size your entire life. The stomach is actually a pretty flexible organ, so it does expand when we eat big meals, but then it goes right back to its normal size when the stomach empties itself about 30, 90, 120 minutes later.

Chiang: Naturally, our stomachs won't shrink, but there are procedures out there where we can actually reduce the volume of the stomach and then help patients lose weight that way. But that requires a procedure.

May: A good analogy is probably a rubber band, right? So a rubber band has a defined size and you can stretch it out if you have a big meal, but it will always go back to that size. And it's not until you're really pushing the limits over and over again that it starts to develop those little breaks, get a little bit wobbly and larger, but generally it has its innate size.

May: "Jumping or exercising after eating will give you appendicitis."

Chiang: What? I have never heard of this. I'm tossing that one out. I have my handy-dandy plushy here. The appendix is this pocket that comes off of the beginning of the colon. Sometimes it can get inflamed or blocked off, and that's called appendicitis. But exercising or jumping around after eating, no. We would be seeing people dropping like flies at the gym if that were the case.

May: First of all, that thing is really cute. And second of all, I agree completely. Can you imagine all the athletes that would be developing appendicitis?

Chiang: Most of the time it just comes about. There's nothing that sort of leads up to it, it just suddenly happens.

May: And, luckily, appendicitis is something that's very treatable.

Chiang: Ooh. So, "You need to wait 30 minutes to swim after eating."

May: So, this is the hogwash that every parent has told every child. The reality is after you have a large meal, your body does shunt blood flow to your stomach and your digestive organs to help you digest this meal. And I think what's happened is that people have then feared that because it's shunting blood away from your arms and your legs and the large muscles that you need to swim, that if you immediately jump into a pool you won't be able to swim or use your arms and legs to save yourself. But the reality is your body has enough blood flow to supply both your stomach and your digestive organs and your legs and arms. There are some people that will experience some abdominal cramping if they swim immediately after eating a big meal. And that's just because the digestive muscles are already busy at work and you're stressing them more by putting them under the exertion of being in a swimming pool. But I don't think we need to worry about drowning risk here.

May: "Probiotics will fix your gut."

Chiang: We wouldn't have jobs if probiotics cured everything about the gut. I think what this statement is trying to get at is that there's a lot about the gut microbiome, the bacteria that live in our gut, that can potentially impact our health. We simply just don't know enough about it.

May: There is an actual bacterial environment that lives in your gut. Most of them are not bad bacteria. They're good, healthy bacteria that you need to have normal bowel movements, to avoid pain and other diseases. But every once in a while, that can get imbalanced. So probiotics became really popular with this concept of resetting your microbiome. But the reality is that the science is so new in this area and there's really very few conditions where we've figured out how to use probiotics the right way.

Chiang: And part of the reason behind this is because there's very little regulation on probiotics by the FDA, for instance, there's very little consistency in the formulations. We don't know what dosage actually works for certain conditions as well. So there's still a lot that we don't know about probiotics.

May: I do think that for some people it has an impact, but it's not a cure-all, and it doesn't work for everyone.

May: Oh, good one. "'I got food poisoning from the last thing I ate.'" In reality, it takes hours, right, for your stomach and your small bowel to process each meal. So it's usually the second-to-last thing you ate. And I think there's a big misconception about this, because patients will come in and swear that it was the breakfast they ate, and I tend to ask them, "Actually, what'd you have dinner the night before?" Or if they're saying that they developed their symptoms in the evening, it's, "What did you have at breakfast?" Because that might be the culprit. How bad is that word, by the way? "Food poisoning"?

Chiang: I know! Who came up with that? 'Cause it's not the food itself that's causing the poisoning, right? The definition of food poisoning, first of all, is very broad. It can involve different types of bacteria, the toxins that they create, it can involve viruses. The key things are to rest and to try and stay hydrated. You want to start with one or two bland items and small bites of that to see if you tolerate it, and then in a few hours, maybe a few more bites. The last thing you want to reincorporate to your diet after a bad bout of food poisoning are lactose products, because the lactate enzymes that line your intestines are some of the last enzymes to come back and to repopulate. So you're really not prepared to digest lactose-containing foods for a while.

Chiang: What? "Women don't need regular colonoscopies"?

May: Is that what it says? I'm going to rip this one up. This one is absolutely a myth!

This is your colon. Unfortunately, a reasonable percentage of us will grow what we call polyps in your colon. They look like pimples, but the dangerous thing is that a small percentage of them, over years and years and years, can develop into colon or rectal cancer. Because unfortunately there's been this myth that colorectal cancer only occurs in men. It's important for women to know that colorectal cancer occurs in women as well. It follows just lung and breast cancer in being the most common cancers for women, and unfortunately it's the third most common cause of cancer-related deaths in women. So all you women out there, get your colonoscopies. Everyone who is average risk for colorectal cancer, meaning that you don't have a family history and meaning that you don't have a predisposing condition for colorectal cancer, should start screening at age 45 or 50.

May: "'I feel really bloated, so it must be IBS.'" To have a diagnosis of irritable bowel syndrome, or IBS, you actually have to meet defined criteria that have to do with your bowel movements and pain. But bloating itself doesn't necessarily mean that you have irritable bowel syndrome.

Chiang: Bloating is so common. Having some bloating here or there is totally normal. That's normal fluctuations depending on what we eat. It's usually related to what we're putting into our bodies.

May: Fiber, which we know is very helpful and very healthy, can cause increased bloating.

Chiang: There are other conditions that can also cause bloating, including bacterial overgrowth or certain intolerances like lactose intolerance. And, actually, there's set criteria in how we define what IBS, or irritable bowel syndrome, is, and bloating isn't technically part of that definition. It more depends on kind of the appearance or the form of the stool, the frequency of the stool, but not necessarily bloating per se.

Chiang: "'I just know I have a gluten allergy.'" Oh, this is also a very good one, because everybody thinks that they have a gluten allergy, and oftentimes it's not true. It's really important to distinguish between celiac disease, which is an autoimmune disease that doesn't allow you to digest gluten, from non-celiac gluten sensitivity. And those are the two most common things that people are confusing when they talk about gluten allergy.

So let's talk about celiac disease first. It impacts the lining of your small bowel, and it makes it impossible for you to tolerate or digest gluten. But to have a formal diagnosis with this autoimmune condition, you need to have testing. The other thing we've seen recently, though, is that there are many people that don't have a positive celiac test but still have some symptoms when they have food with gluten. So we don't want people to be on a celiac diet unless they really have celiac disease. We want people to get the nutrition that their particular body needs to function and process normally. And unfortunately, we have such a problem in this country with inappropriate diets that people are putting themselves at harm.

Chiang: When you're hearing bold health claims online, double-, triple-check, reach out to your doctors to ask whether or not what you're reading is true, if there's any science behind it. Look at the science yourself. Just keep asking questions. And we're always happy to answer those questions and help out in whichever way we can.

May: The way that I think about it, everyone wants to be able to eat comfortably and to be able to poop. We give people that power to enjoy their food, to feel comfortable without abdominal symptoms, and to go on enjoying their life.