Can someone give me an estimate of how long food takes to go through your digestive system.

July 21, 2012 1:29 PM

Can someone give me an estimate of how long food takes to go through your digestive system.

This is a rather stupid but also serious question.

I've always wondered and gotten several different answers from people when asking them.

The serious side to it is that I have (chronic) acid reflux and am wondering how long it takes my food to affect this condition - so I can work out exactly what foods irritate my stomach/esophagus.

The stupid part is that currently I'm having a bout of awesome gas (awesome being a term that for most people, would be translated as a horribly disgusting smell) and I'm wondering how I would be able to tell what food made it happen. I would like to know this so a) I can avoid eating it when seeing a girl. And b) eat some on purpose if I feel the need to exterminate my colleagues at work.

posted by sockpim to food & drink (20 answers total)

Here is what a gastroenterologist at the Mayo Clinic says: "Digestion time varies depending on the individual. For most healthy adults, it's usually between 24 and 72 hours. After you eat, it takes about six to eight hours for food to pass through your stomach and small intestine. Food then enters your large intestine (colon) for further digestion and absorption of water. Elimination of undigested food residue through the large intestine usually begins after a total of 24 hours. Complete elimination from the body may take several days."

I'm pretty sure I've read that meat takes much longer than produce, and that makes sense when you think about it.
posted by Houstonian at 1:34 PM on July 21, 2012 [1 favorite]

Actually, it depends on the food in question. Some foods are easier, and thus quicker to digest, and some foods take much longer. I don't know specifics, but the range is probably between 20 minutes and a few hours.
posted by blurker at 1:35 PM on July 21, 2012

Sorry, I was thinking of how long it would take for the food to start creating gas. If you're asking how long for it to get completely through your system, Houstonian is closer. And yes, meat takes more time to break down.
posted by blurker at 1:40 PM on July 21, 2012

But if you're thinking about your reflux, you don't want to know how long food takes to exit your system, you want to know how long it takes to start affecting your reflux, which might be very different. I would guess it would be much more immediate. But you might also find that the types of food you eat have a buildup effect so that your reflux is worse after you've eaten badly over the next week. I'm sure there's literature about this - I'm taking off the top of my head!
posted by kadia_a at 1:40 PM on July 21, 2012 [1 favorite]

I have (chronic) acid reflux and am wondering how long it takes my food to affect this condition - so I can work out exactly what foods irritate my stomach/esophagus.

Whatever your reason, Houstonian's right that everyone is different in this regard. My digestive system takes forever (IE a day or two, usually, to pass what remains of a meal) compared to my roommate's, who seems to be hungry again half an hour after we've eaten. Different foods can affect processing time as well, per blurker.

What I recommend is keeping a food diary and record every meal. You'll start to notice patterns both in processing times and diverse reactions (bad gas) over time, but over the years you may notice the patterns shifting.
posted by carsonb at 1:41 PM on July 21, 2012

I'm pretty sure I've read that meat takes much longer than produce, and that makes sense when you think about it.

The digestive system is pretty much a long tube. Different foods can't pass up other foods.

Reflux and gas might happen coincidentally, but they aren't really related as far as the mechanics of your gut works. Reflux is your stomach gurgling up acid into your esophagus, and gas is bacteria in your intestines digesting the food along with you.

Reflux is caused by different things, and when it happens will depend on what thing yours is caused by. But it usually starts with some kind of insult to the esophageal sphincter, causing it to misbehave.
posted by gjc at 2:04 PM on July 21, 2012 [1 favorite]

If you want to time your own digestive system from mouth to anus, eat some maize (corn, popcorn) and record when you see hulls in your poo. It won't tell you how long you take to make gas, but give you a nice idea of how long the whole process works.
posted by Jehan at 2:15 PM on July 21, 2012 [1 favorite]

You can always gauge for yourself by eating a Tracer Food.
posted by scose at 2:20 PM on July 21, 2012 [2 favorites]

Sesame seeds also work to tell you how long you take.
posted by madcaptenor at 2:28 PM on July 21, 2012

Also if you drink a lot of blue Kool-Aid. Scariest thing to see when you don't know to expect it.
posted by Houstonian at 2:46 PM on July 21, 2012 [1 favorite]

I'm pretty sure I've read that meat takes much longer than produce, and that makes sense when you think about it.

Meat digests more quickly and more easily than other foods, so I'm not sure why you would think this makes sense.
posted by rr at 4:49 PM on July 21, 2012

The bowel transit time for me seems faster when I eat, for example, 16 ounces of prunes versus a 16-ounce steak.
posted by Houstonian at 5:19 PM on July 21, 2012

Last I read (sorry, no cite, it was a long time ago) it takes about 15 minutes for food to get from your mouth to your stomach.

I have issues with cooked tomatoes (spaghetti sauce, etc.) and will, generally, start having reflux between two and four hours after eating it.
posted by deborah at 6:50 PM on July 21, 2012

Disgusting solution:

Eat corn. Whole kernels.

Wait, and look at your poop. See corn? That's how long it took!

Beets could also work, especially if you want to see how long it takes to for what you ate to have an impact on your pee.
posted by Sara C. at 8:04 PM on July 21, 2012

I suggest using Pepto Bismol as a gauge. It will darken your stool significantly, so you don't have to look too closely (gross) every time you have a BM like you would with undigested foodstuffs. You will notice.

I have IBS and it really helps me to know exactly when the offending food was consumed.
posted by petiteviolette at 10:28 PM on July 21, 2012

One possible solution to chronic acid reflux is taking generic omeprazole (Prilosec) every day, like 20 mg should take care of it. I take a pill just when i feel the reflux coming on (maybe once a week) and that's enough to deal.

You should also know that chronic acid reflux - like really, really chronic - can lead to a condition called Barret's esophagitis, a precursor to esophageal cancer. I say this as a med student. That's why I just take the Prilosec to deal.


posted by 254blocks at 1:03 AM on July 22, 2012

Thanks for the suggestion 254blocks, but I've already tried taking Omeprazole and it made me vomit a lot of fresh blood and stomach bile. It also made my skin extremely photosensitive.
posted by sockpim at 5:26 AM on July 22, 2012

sockpim, there are other options if omeprazole had side effects for you, like ranitidine.

generally, foods would affect your reflux within a few hours (while the food is in your stomach). That is why people with reflux are advised not to eat within a few hours of going to bed, since lying down puts you in a position to have worse reflux, gravitationally speaking.
posted by treehorn+bunny at 9:06 AM on July 22, 2012

If you vomit "a lot of fresh blood," that usually means you should see a doctor, not just try to figure things out with a food diary. Vomiting blood is often caused by something that won't fix itself without some kind of intervention. And it still counts as bleeding! If you bled that much from a cut on your arm and felt you should probably get stitches, then bleeding a similar amount from your stomach is a similar problem -- you should see a doctor to make sure you're not losing too much blood.

Incidentally, are you pooping dark black, tarry-looking stuff at all? GI bleeding that gets digested and pooped out often looks like that, and it tends to smell pretty awful. Your initial comment about "awesome gas" makes me wonder. If you are, you really need to see a doctor this week, ASAP, and to the emergency room if you are vomiting more blood or having large amounts of diarrhea.
posted by vytae at 10:14 AM on July 22, 2012

Sorry if it sounded like I meant in general. I meant being on the Omeprazole made me vomit bile and fresh blood. I've weaned myself off the ranitidine meds for the last 6 months. My poop is a normal light brown colour and am now pooping with no constipation again thanks to a heavy fibre diet.
posted by sockpim at 2:35 PM on July 25, 2012 [1 favorite]