What causes Montezuma's Revenge?

I always assumed there were bacteria/germs/bugs in the water that Americans didn’t usually encounter, and that our intestinal flora went on a rampage for a few days.

But I’ve just come back from a Mexican resort, where it was repeatedly explained as the result of “high mineral content”. No one said what minerals.

Is this the truth, or is “mineral content” just a euphemism that sounds better to the tourists?

I’d say the tour guide was just being a little odd. I mean, even if there were notable differences (and different places will have different mineral content) the bacteria would be much more important. Heck, you still can get the trots when you go to a place with less sanitary water supplies.

Sounds a bit strange.

There’s some recent evidence that high mineral content in water (particularly calcium salts) inhibits bacterial growth in the gut.

Maybe they’re interpreting that to mean that because they (the locals) regularly drink the high mineral content water, they don’t suffer from diarrhea as often.


Your body is used to the bugs it encounters in your diet and in the water supply you feed it.
When you travel to somewhere where the bug soup is different to what you are used to, your insides can react pretty badly.
That’s about the size of it.
Blaming the mineral content sounds very fishy to me, but I am not a gastroenterologist.

Desmostylus if mineral content in water inhibits bacterial growth in the gut, how can this be good? The bacteria in there are doing a job and if people are killing them off then are they suffering because of it?

I lived once in an area of Sicily where the tap water couldn’t be consumed because the volcanic aquafer it was drawn from had high concentrations of magnesium. Drinking the water would have been like guzzling down half a bottle of Phillip’s Milk of Magnesia every single day.

Needless to say, we drank and cooked with bottled water.

There’s a precarious balance in our intestinal flora. Some of them we get on well with, and some of them we don’t. Sure, “The bacteria in there are doing a job”, and that job is to reproduce themselves. You get loads of E. coli in there doing their job, and you end up with Montezuma’s revenge.

It’s the strange (foreign) strain of e-coli that causes tourist’s trots. Avoid uncooked food and/or drink and no problems. Drink local water and voila Tourist’s Trots!

You can get vast variations in mineral content by going to different places in the US (My home town has high copper. Salt Lake City has incredibly high calcium. Areas with hot springs have high sulfur.), yet I’ve never gotten “Montezuma’s Revenge” going to these places. My guess would be exotic bacteria (although I’ve never been to Mexico).

I don’t know about mineral content… but I’m not sure of the bugs, either.

When I first started working in Mexico, I really, really sick the first night there. Then I was fine for a while. Then I got sick a couple of more times, each time less severe. Now I think I’m immune, and never have problems when I go back there. Of course I don’t eat or drink anything the Mexicans themselves don’t.

When I brought my wife here from down there, I was fully expecting that she’d get sick, too, just from the change in bugs that are floating around. It never happened. I don’t know if she’s just stronger, or if the chlorine in the water alone had an effect, or whether it’s just something else.

I’ll be able to put it to the real test in a couple of days, though. My brother and mother are going down there with us this time – if I don’t get sick and they do, maybe we’ll know something. Of course with such small experimental and control groups, maybe it won’t be valid.

Well, in some places, just brushing your teeth and then rinsing your toothbrush is all that is needed. Or eating veggies rinsed in local water. So, this is definitely a sign of germs being the cause, not mineral content from gulping water.

The Dehli Belly, or Montezuma’s Revenge is from different strains of bacteria. Your body flushes out millions of the critters via your trip to the bathroom.

I always understood it to be from e-coli types. I also understood that you are immune from your own e-coli, and eventually from your families when living with them and going through cross contaminiation over and over again.

Another point against mineral content: Boiling the water makes it OK. That wouldn’t happen with minerals, but it would with bacteria or other biological nasties.

So could I eventually get my body accustomed to the foreign strain and I could eventually drink the water with no ill-effects?

I’ve seen nature shows where they show native jungle dwellers drinking straight from a river. From what I’ve read, that would just about kill me to drink unboiled water from a jungle river. Are the native peoples’ bodies just used to the bacteria in the river?


That’s not a very satisfactory answer, Chronos, because boiling does affect mineral content, e.g. by causing calcium carbonate to precipitate.

I’m surprised you had never come across this. “High mineral content” is universally used to explain away your dodgy gut :slight_smile:

FWIW, I went on a 6-month round-the-world trip a year ago, ate at all manner of dodgy street stalls in Cambodia, Mexico etc etc and didn’t get sick once. (Although I went to Morocco in the summer for 10 days with my girlfriend and we were both fighting over the bathroom for the last couple of days! So go figure…)

Here’s an interesting exercise - Google for "high mineral content" travellers - it’s a common excuse!