Digestive system question, possible TMI

Ok in school I remember being taught that digesting food takes 24 hours. So how come when I eat certain foods I can see them in the toilet bowl an hour or so after I eat them?

You can’t. Unless you’re really sick (and then you probably are too sick to care).

It takes longer than that for food to go thru your digestive tract. In fact, it usually takes up to 2 hour for foods to jut go thru your stomach. Some foods (fats, carbs) are digested in just 3-4 hours, others like proteins take longer. But these are digested, so they aren’t coming out the outer end for you to see.

I think you are miscalculating this.

You’ve never eaten corn?

Frequently. Heck, we usually grew 20 acres or so of sweet corn on the farm, and ate a lot of it.

But again, the kernals you see coming out that end are undigested ones. Most of them, that were digested, you won’t recognize.

Normal digestion pretty much follows the standard bell curve, with the peak somewhere around ten hours for entry to exit but lots of variation on each end.

There’s a billion or so ways for people to not have normal digestion, with the food taking either much faster or much slower than normal.

Corn kernels are one of the classic foods to show up in the stool, because people tend not to chew the kernels properly, but just swallow them with a gulp. If they remain whole they are remarkably resistant to the normal breakdown by acids and enzymes. Peas and other foods that are small and have a hard outer coating are like this as well.

Food that is going to be digested tends to linger in a thin but vital layer of stagnant water next to the microvilli on the insides of the intestines, which gives the body a better chance of absorbing the nutrients that otherwise would be pushed along by peristalsis in the chyme, the liquid mass that food turns into. Large, undigestible particles are going to stay in the chyme and take less time to go through the body.

But an hour? I have my doubts. I’m betting that the “or so” in the OP is really a lot longer than that.

I’m not the OP, but I was pondering posting a similar question recently. Normally I’d say that my digestion takes a normal amount of time (12-24hours).


However, I have noticed that when I eat fast-food hamburgers, it seems speeded up. I can eat fast food chicken burgers or mexican or whatever without problems. But if I eat a burger from, for example, McDonald, then I’m urgently only the toilet in one hour or less. With noticably runnier than normal stools.

I don’t think it’s just a case of having an upset stomach and then mis-attributing it to recently eating a burger. It’s happened on at least four or five separate occasions spread over several years. Like I said, it’s only if I have a fast-food burger, and it’s usually worse if I have a burger and fries combo. Maybe it’s all the grease? Dunno.

Google for “gastrocolic reflex.”

The simple version can be found here.

But many people have begun to associate some of the symptoms of Irritable Bowel Syndrome with the gastrocolic reflex"

Check the rest of that page as well. I have no idea whether any of this applies to you. However, there are medications that will reduce bowel spasms and excess motility. It wouldn’t be a bad idea to make an appointment with a gastroenterologist.

Many people have laxative effects after various eating fast foods (esp hamburgers) , but it’s not your digestion speeding up, it’s your colon.