There is nothing more miserable than problems with the gastrointestinal tract when on a trip.  From heartburn to diarrhea a change of environments seems to make these maladies common.  I hardly ever get heartburn except for when I go above 15,000 ft.  For some reason I start having problems at this altitude.   Pepto-Bismol tablets seem to do a wonderful job for me most of the time.  When they stop getting the job done I switch to Zantac 75 which is available over the counter and I have never had to use anything stronger.

    When the trouble is burning at the other end life seems fruitless.  There is nothing worse than having to sprint out of the tent every few minutes because of diarrhea.  For mild cases I start with Clidinium.  This drug is also used as a mild sleep agent so beware if you need to be alert.  This is true of most prescription anti-diarrhea medications.  I never carry over the counter diarrhea medications as I don't have time to wait for relief when at altitude.  For serious cases I keep Lomotil.  I have had good luck with this product.

    When the stomach is in a uproar and you can't keep any food down we usually go straight to the Cipro in the mountains.  You cannot afford to stay sick like this for long so jumping on it with something powerful immediately is important.