Dreaded Backpackers Diarrhea and Vomiting. How do you manage it?

Backpacker in tent
Average read time 4 min

One night in the Santinoni Range in the Adirondacks, my teenage son got violently ill. He had no fever, but he had backpacker diarrhea and lots of stomach cramps. Our planned climb of the range was not to be. We did some backcountry gastrointestinal (GI) management (fluids and rest) and hiked out the next day. He slept the 4-hour drive home. We don’t know why he got sick, but he was washed out and fatigued; thus, we opted to evacuate.

Various studies have demonstrated different rates of backcountry gastric distress. Results ranged from 7% to 63% of hikers. Many authors have reached the same conclusions; that both poorly treated groundwater and poor camp hygiene are responsible for gastric distress.


A word of caution on abdominal pain

Abdominal pain is a serious symptom that should be evaluated carefully. The intensity, location, duration, and type of pain will give clues to the condition’s seriousness. The pain associated with other symptoms should guide recommendations for evacuation. Abdominal pain can be an indicator of heart attack, ulcer, gallstones, ovarian infection, kidney stones, bowel obstruction, to name a few. These conditions are beyond the scope of this article. See the end of this article for resources on wilderness medicine.

Prevention is key

We always start with prevention. In this case, two things are common causes of backcountry GI problems. First, and probably common, is poor hygiene in camp. Yes, people going to the bathroom and not sanitizing their hands after. Gross!

A study on backpacking hygiene

A study from the Journal of Travel Medicine looked at the issues addressing illnesses, water disinfection methods, and hygiene while in the backcountry. They did a retrospective study using questioners of two hundred and eighty backpackers compiled 38,940 wilderness exposure days. 56% of the cohort experienced diarrhea. The study found that both drinking untreated surface water and poor hygiene after urination and defecation increased diarrhea rates. 

The authors concluded: “Lack of hygiene, specifically handwashing and cleaning of cookware, should be recognized as a significant contributor to wilderness gastrointestinal illness. Hikers should routinely disinfect water and avoid untreated surface water.”

A study on clean water

The second is the carelessness in treating surface water. You must treat water to remain healthy in the backcountry and when returning home. A study of water supply near Appalachian Trail shelters in the Great Smoky Mountains National Park found that 7 of 10 summer water samples contained coliform bacteria and 6 of those 7 for E Coli.

Related post: Sawyer Mini Water Filter System

Merely using a water filter and a chemical treatment could prevent most infections from waterborne sources.

Mini Filter with Pouch and Straw Attached
Scott | copyright Challenged Hiking Mini Filter with Pouch and Straw Attached

But what if I (we) get it anyway?

The person with gastric distress may experience vomiting or diarrhea. In both instances, the individual may be losing extensive fluid volume. So the first and essential intervention is replacing lost fluid. Have the individual drink fluids with electrolytes to prevent hypovolemia, dehydration, acid-base imbalance, and serum electrolyte abnormalities. If the fluid replacement doesn’t prevent dehydration, evacuation is indicated.

Symptoms of dehydration  in adults include:

  • extreme thirst
  • dry mouth
  • urinating less than usual
  • dark-colored urine
  • lightheadedness
  • fatigue
  • decreased skin turgor
  • sunken eyes or cheeks

With vomiting or diarrhea, keep the person warm and as comfortable as possible. Anxiety may make the conditions worse. Help them manage periods between vomiting or diarrhea by checking how they are feeling. Keep a record of the number of times when they experience vomiting or diarrhea (and other vital signs). Keeping this record can help you judge the illness’s progress and what steps should be taken as it runs its course.

Related post: Waterborne Illness and camp hygiene.

Backpacker diarrhea

Diarrhea is associated with many illnesses, and knowing the exact cause is often elusive, especially in the backcountry. However, there are some necessary actions that the hiker can take to help.

As above, start with fluid replacement. Using an over-the-counter medication may help relieve diarrhea. Check with your pharmacist or doctor on which will be the best for you and your hiking team. Once diarrhea has lessened in frequency with decreased cramping and an increased appetite, the individual can be encouraged to eat easily digestible foods like rice, crackers, oatmeal, or cream of wheat. Avoid high fat, high processed foods. Feed as tolerated. Most people that experience diarrhea will have discomfort at the anus, even using toilet paper. A cream like 1% hydrocortisone lotion may help.


Vomiting may be caused by something as annoying as anxiety or insidious as a head injury. Suppose you suspect a head injury or poisoning, extreme abdominal or chest pain, mental status changes, high fever, or the hiker is very old or young; in that case, it is an emergency. For non-life-threatening causes, there are necessary steps to help the ill person.

Fluid replacement, as indicated above, is an intervention of choice. A hiker can use an over-the-counter medication to prevent or treat nausea or vomiting. Check with your pharmacist or doctor on which will be the best for you and your hiking team. As improvement is noted and indicated, the ill hiker should give a bland diet.

When to evacuate

If after 24-hours the condition does not resolve, evacuation is warranted. If the person’s illnesses or symptoms worsen or change before 24-hours, consider evacuation. Bloody stools or yellow or green vomit, or blood in the vomit are indicators for evacuation. Fever is another indication of evacuation.


Medicine for the Outdoors: The Essential Guide to First Aid and Medical Emergencies

Find a wilderness first aid class near you.

A clean hiker is a happy (and healthy) hiker.

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