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