Speaker 1: Welcome to brain stuff from how stuff works. Hey, brain stuff,
Speaker 1: it's Christian Seger. Did you know that of healthy young
Speaker 1: people claim that drinking coffee induces a desire to defecate.
Speaker 1: And you know what's crazier than that? A significantly higher
Speaker 1: proportion of responders were women. Sorry, ladies, you are more
Speaker 1: prone to bowel sensitivity than dudes. They think it's because
Speaker 1: caffeine and high temperature increase the sensitivity of the intestines.
Speaker 1: It's called motility. That's what ensures paristallysis. This is why
Speaker 1: hospitals give some patients coffee after surgery. It can help
Speaker 1: get their colonic muscles contracting and relaxing again. It's almost
Speaker 1: like eating an entire meal. And did you know that
Speaker 1: coffee also gives the colon less time to reabsorb water,
Speaker 1: so it also leads to looser stools. But sometimes dairy
Speaker 1: products lots of sugar or even sorbitol can also act
Speaker 1: like a laxative. Coffee primarily reduces esopha geel sphincter pressure,
Speaker 1: stimulating secretion from the stomach and large intestine. In fact,
Speaker 1: people who drink iced coffee that's decaffeinated they report the
Speaker 1: same paristalsis effect, So it can't just be caffeine or
Speaker 1: water temperature, can it. Well, that's probably because hot water
Speaker 1: doesn't have an effect on recto sigmoid motility. So there's
Speaker 1: probably a trigger component in coffee other than caffeine. Since
Speaker 1: the speed that coffees gastro colonic response happens in is
Speaker 1: within four minutes after drinking it, scientists think there's an
Speaker 1: indirect action involved via either the intestinal lumen or the bloodstream.
Speaker 1: It could be acting on epithel receptors, possibly media it
Speaker 1: did by neural mechanisms or gastro intestinal hormones like gastron
Speaker 1: which increases colonic spikes and motor activity. So it's not
Speaker 1: like coffee could reach your colon in four minutes anyway.
Speaker 1: But colo sister kinin is another possibility. It's also a
Speaker 1: putative mediator of gastro colonic responses, but there's no data
Speaker 1: yet on whether coffee causes its release. It could also
Speaker 1: be exorphines that bind to opiate receptors in the brain
Speaker 1: and the gut wall. They're also necessary for a colonic
Speaker 1: response to food. But wait a minute, I've heard for
Speaker 1: years about how coffee has dehydrating effects. Because it's a diuretic,
Speaker 1: shouldn't it cause constipation instead of all this other stuff? Well,
Speaker 1: research shows that coffee is only diuretic when consumed in
Speaker 1: large amounts, like more than six hundred milligrams a day.
Speaker 1: But that is barely more than point zero two ounces.
Speaker 1: So I can drink one or two cups of coffee
Speaker 1: a day and there won't be any significant difference in
Speaker 1: my urine output. But wait a minute, who only drinks
Speaker 1: two cups of coffee a day? Check out the brainstuff
Speaker 1: channel on YouTube, and for more on this and thousands
Speaker 1: of other topics, visit how stuff works dot com