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Food transit time

How many hours after eating a certain food would you know if is a safe or unsafe food? I read that it takes 6-8 hours to pass the small intestine and up to 24-40 hours to pass the large. So say I eat pretzels at 6 p.m., when would I know this is a safe food for me? I am tracking everything I eat and making a safe list. Thank you all so much. maryann

5 Replies

Can take three to five days


Hi, everyoneis different and, the test is usually the corn test, weather on the cob are loos-

mine took 16 hours to pass all the way through. Eat a good amount of corn to find out.

Have fun with this sciency bit.

S x


you mean the actual trasit time of consumed food ?? or when will you get a bad reaction after eating certain food ?? sometimes the trigger (unsafe food) will cause a bad reaction (spasms /diahrrea/ gas/ bloating ) even when it is still up there and haven't reached the colon yet because in our case (IBS) the stomach will send early signals to the large intestine (colon) that will activate its nerves in an abnormal way to cause any of the IBS symptoms i mentioned earlier ..thus for example you could have urgency and an early BM even when the digested food is still up in the stomach ..This is what my GI consultant explained to me when i asked him how come it takes only 30 minutes or less after eating the (Unsafe food ) to cause severe spasms and sudden urgency ??!

Hope this answers your question and help you with your food diary 🌸


Yesterday at 2:00 I had Salmon Teriyaki and today at 8 a.m. I am fine. When would I determine that Salmon Teriyaki is safe for me to eat? In four days I wouldn't have a clue with the other food I eat in between. Hopeless....


I think it's very hard working out what foods are triggers, for exactly the same reason, the reaction time can be anything from very short to a few days. But it sure helps that you were fine from 2 one day to 8 am next day! Write everything you eat down, and the times, till you figure it out. If you can, try and eat relatively few foods - if you can find just a few that give you a balanced diet and don't give symptoms, you can try adding others back in gradually. I have at least mild symptoms most of the time, and I find I notice more easily when they've been mild and suddenly get worse, but if they were bad and get a bit better gradually I don't really notice that.

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