字幕表 動画を再生する 英語字幕をプリント [♪♩INTRO] Everybody poops. It's one of those facts of life. The average person does it anywhere between three times a week and three times a day -- so by the time you're an adult, you're a very experienced pooper. But sometimes, even with the right diet and exercise, you need a little help with your number two. And that's where laxatives come in. Constipation is pretty common, with anywhere between two and 30% of people experiencing symptoms at any given time. It can be caused by lack of exercise, many medications, or certain diets. Changing your habits might solve the problem, but if not, there are a whole bunch of laxatives to make your pooping experience more enjoyable. The most common type are called bulk-formers, and they're basically concentrated doses of dietary fiber. Dietary fiber is a broad term for the parts of plants we eat, but that our bodies can't digest, and you'll find it in things like whole wheat breads and vegetables. There are two kinds of it: soluble fiber, which can dissolve in water and form gels, and insoluble fiber, which doesn't. Bulk-forming laxatives add soluble fiber to your intestines, which makes your stool full of soft, squishy fiber-gel. That makes them larger and heavier, while keeping them soft and easy to pass. These are some of the safest laxatives to take long-term, which makes them popular. But if fiber-gels aren't your style, you have some other options. Another kind, osmotic laxatives, work by making the concentration of certain salts or sugars higher in your intestines than outside them. To equalize the concentrations and get things back to normal, water from the rest of your body is pulled into your intestines. And that creates a waterslide for anything inside your colon. If you've ever had to hit the bathroom after eating sugar-free gummy bears, this is why. They're sweetened using sugar alcohols like maltitol, which is a potent osmotic laxative. There are also stimulant laxatives, which increase the number of contractions in your intestinal walls by stimulating the nerves controlling them. The contractions cause stool to travel faster through your digestive tract, so this kind of laxative tends to act the fastest. Now, most laxatives are known for helping out with constipation, but they can be helpful for other things, too -- like, if you've just had surgery and shouldn't be straining your muscles in the bathroom. To make regular bowel movements easier to pass, there are lubricant laxatives, like mineral oil, that coat your intestinal walls to make them slippery, and emollient laxatives, also called stool softeners. Those decrease the surface tension of fatty stools, allowing them to absorb water and become soft -- like how soaps and detergents let water and oils mix when you're washing your hands. So no matter your poop situation, there's a laxative for you. At the end of the day, a healthy diet and exercise go a long way in keeping your body running smoothly. But the next time you're feeling bloated and wishing for a visit from the poop fairy, you have options for helping nature along. Just maybe don't choose that bag of gummy bears. Thanks for asking, and thanks to all of our patrons on Patreon who keep the answers coming! If you'd like to submit a question, you can go to patreon.com/scishow. [♪♩OUTRO]