Backcountry Diarrhea: Prevention and Treatment in the Wild

Understanding Wilderness-Acquired Diarrhea

When you’re out in the wilderness, even the smallest health issue can quickly turn into a survival problem. One of the most common and underestimated dangers is backcountry diarrhea.

A number of things can cause backcountry diarrhea, the most common are drinking contaminated water, poor hygiene, or food mishandling. Any of these can dehydrate you fast, reduce your energy, and make it harder to think clearly or travel safely. Knowing how to prevent it and what to do if it happens can make all the difference on a trip.

Common Causes of Diarrhea on the Trail

Most wilderness diarrhea cases come from microorganisms in untreated water, including Giardia, Cryptosporidium, and bacteria like E. coli. But water isn’t the only culprit. Poor camp hygiene, dirty cookware, or failing to wash your hands before eating are also leading causes.

Even a small mistake like rinsing a cup in untreated stream water, or eating food with unwashed hands, can be enough to introduce harmful microbes into your system.

Recognizing the Symptoms

The first signs of wilderness-acquired diarrhea often appear within 6-12 hours of exposure, though some infections can take longer to develop depending on the organism. The main symptoms may include:

• Loose or watery stool

• Stomach cramps or bloating

• Nausea and fatigue

• Fever or vomiting

These symptoms can be mild at first but may worsen quickly. The biggest risk is dehydration, which can become dangerous in as little as a day, if not addressed.

How to Prevent Diarrhea in the Wild

Prevention is your best survival tool. Here are the most reliable steps:

Treat All Drinking Water

Never drink straight from streams, rivers, or lakes —even if they look clear. Always use one of these water treatment methods:

• Boiling: The most effective water treatment method it to boil it; bringing the water to a rolling boil for at least 1 minute (3 minutes at high elevations).

• Filters: Lightweight backcountry filters can remove protozoa and bacteria but may not always remove viruses.

• Chemical Treatment: Iodine or chlorine dioxide tablets are effective backups.

Practice Camp Hygiene

Clean camping is essential to wilderness survival.

• Wash or sanitize your hands before eating or handling food.

• Whenever possible, use the three-bowl method when cleaning dishes: one for washing, one for rinsing, and one with treated water plus a sanitizing solution.

• Keep raw and cooked foods separate.

Food Safety Tips

• Avoid bringing perishable foods unless you can keep them cool.

• Cook food thoroughly.

• Store food securely away from animals and insects.

What to Do If You Get Sick

Even with the best of precautions, a backcountry illness can still strike. Here are some tips on how to manage it in the field:

Stay Hydrated

• Drink small sips of treated water frequently.

• If available, make an oral rehydration solution (ORS): mix 1 liter of clean water with 6 teaspoons of sugar and ½ teaspoon of salt.

Rest and Conserve Energy

Your body needs energy to fight off infection. And so if you find yourself suffering in the backcountry, do your best to avoid overexertion and rest whenever possible.

Consider Medication

• Over-the-counter medications like loperamide (Imodium) can slow symptoms.

• If you’ve packed antibiotics prescribed for travel, they can be useful against bacterial causes.

• Always use medications cautiously and follow instructions.

Know When to Turn Back

Go back and seek medical attention as soon as possible if you experience any of the following :

• Diarrhea that's severe or lasts more than 3 days.

• You see blood in your stool.

• You cannot keep fluids down.

• You feel extremely weak, dizzy, or disoriented.

Preparing Before You Go

Backcountry diarrhea is a lot more easily preventable with adequate planning. Before any trip:

• Pack a lightweight water treatment system. For some options of reliable water treatment systems, click here.

• Include rehydration salts or supplies to make ORS.

• Take hand sanitizer, biodegradable soap, and a small first aid kit. Most of these items are small and can be easily added to a backpack.

• Research common risks in the area you’re traveling. If you know about the potential pitfalls, you can do more to prepare to avoid/deal with them beforehand.

Final Thoughts

Backcountry diarrhea is more than just an inconvenience — it can quickly turn into a survival emergency. By treating all water, maintaining good hygiene, and knowing how to respond if you get sick, you can keep yourself safe and strong on the trail.

Prevention is always easier than treatment, and with the right preparation, you’ll be able to enjoy your wilderness adventure without worry.