Traveler’s Diarrhea

Robert H. Page, MD and Curtis P. Page, MD are authors of the MEXICO: Health and Safety Travel Guide and Yucatan: Healthy Traveler’s Handbook.

What it is?

Diarrhea is defined as 3-4 loose stools in a 24-hour period. Diarrhea when traveling to a foreign country is common with some studies claiming that it may effect up to 50% of travelers that stay at least one week in Mexico. Many environmental or infectious factors can contribute to or cause diarrhea. Often times TD is just the result of new, unfamiliar bacteria battling it out with your own natural flora for supremacy of the intestinal tract. The body’s immune system responds to the chemicals of warfare emitted by these bacteria by increasing fluid production; hence diarrhea is the result. Often times it is only time that is necessary to adjust to the new bacteria and diarrhea resolves without treatment. All that is needed is to keep up with your fluid intake wait for nature to take its course; most cases of simple TD resolve in about 48 hours. Sometimes the bacteria can be dangerous however and some knowledge about prevention and how to recognize and treat a more serious case can be helpful.

Associated Symptoms

Nausea, vomiting, abdominal pain and cramps, low grade fever and general malaise plus of course, 3-4 loose stools per day. These symptoms are generally benign and dehydration is our main concern.

Bloody stools and high fever are indicative of more serious causes of TD. If you are bleeding into your intestinal tract it usually means that the bacteria you have ingested are invading into the wall of your bowels. If these bacteria or their toxins enter the blood stream you may experience chills, sweats and/or fever greater than 101.5° F. Infections with Shigella, Salmonella or Enterotoxic E.Coli may result in forms of more serious diarrhea that call for specific treatments and precautions. If you have blood in the stool, fever, chill or sweats associated with your TD you should take antibiotics and consider seeing a doctor.

See a doctor if you have diarrhea that persists for longer than one month.

What causes it?

Since contaminated foods and water are the primary source of intestinal illness for travelers we recommend that travelers take certain steps to avoid exposure: Never eat anything raw that you have not peeled yourself. All types of raw food can be contaminated. Salads, uncooked vegetables and fruits are often contaminated. Raw shellfish or sushi can be infected with parasites if not inspected properly. Do not eat food from street vendors. Don’t use tabletop salsa as your condiment. Studies have shown that up to 75% of tabletop salsas left out in restaurants are contaminated with infectious E. Coli. Always drink bottled, purified water. If purified water is not available boil it for at least one minute or treat the water with iodine or chlorine tablets or liquid that can be purchased at most stateside pharmacies or sporting goods stores.

Infants less than 6 months of age should be breast fed or given pre-packaged, commercial formula products reconstituted with boiled or purified water.

Studies have shown that you can prevent TD if you take bismuth sulfate. Two tablets or two tablespoons of liquid four times daily is the recommended dosage (not to be taken in pregnancy). We generally recommend that you don’t take common antibiotics (CiprofloxinÔ, Bactrim DSÔ or Ampicillin) for prevention. Antibiotic overuse has led to unwanted side effects and bacterial resistance making many common antibiotics useless in diarrhea treatment. Nevertheless, thanks to recent developments, there is a new antibiotic that can be taken for TD prevention and the evidence suggests that resistance and harmful side effects are uncommon. XifaxanÔ (Rifamixin), recently approved by the FDA, has been shown to prevent TD in up to 90% of cases. It is easy to take, 200 mg once daily, and it is not absorbed by the intestinal tract making systemic side effects and drug interactions rare.


Contaminated foods and water are the source of bacterial, viral and even parasitic infections. Bacterial are present in most public water supplies in Mexico although there are some communities that tout sterile systems. Foods that have been prepared with unpurified water are high risk. Poorly cooked meats and other food entities are also to be avoided.

Non-infectious factors may influence the gastrointestinal tract and cause loose stools. Alcohol consumption, tobacco use and dietary discretions are well known offenders. Lactose intolerant individuals cannot digest dairy products. Jet lag and fatigue may contribute to the problem. Stress and anxiety can also cause a “nervous stomach” that may lead to diarrhea. Chronic sufferers may have Irritable Bowel Disease (IBS) if they have a long history of diarrhea. Some medications have diarrhea as a common side effect.


If you don’t have fever, chills or blood in the stool your main concern with diarrhea treatment is to avoid dehydration. This is especially true with very small children, especially infants, or with the elderly and/or debilitated. Dehydration is not very well tolerated in adults with heart conditions or on multiple medications that are used to treat the kidneys or the heart. If your diarrhea is significant and you are in a higher risk category we advise that you seek medical attention as a precaution.

For infants and children, prepackaged Oral Rehydration Solution (ORS) is available in most Mexican pharmacies. A common, North American equivalent of ORS would be PedialyteÔ. ORS is a mixture of purified water, salt and sugar in amounts that the body needs to absorb the water from the intestinal tract. The general rule is to give 2-4 ounces of ORS for any loose stool or episode of vomiting in children under the age of 2. For adults or larger children (over 2 years of age), ORS may be used but it may be more cost effective to use a soup broth or water and saltine crackers. Homemade ORS can be made with 1 liter of cooled, boiled water mixed with 6 teaspoons of sugar and one teaspoon of salt. If nausea and vomiting is present and the individual cannot hold down the treatment, we recommend that you see a doctor.

If you have fever, chills or bloody diarrhea you need antibiotic treatment. Antibiotics such as CiprofloxinÔ or Bactrim DSÔ (Trimethoprim-Sulfamethoxazole) are standard and reliable although antibiotic resistance is on the rise.