Stomach Illness on a Nepal Trek: Prevention, Medication and Recovery

More trekkers in Nepal lose a day to their stomach than to anything else. It is usually a nuisance rather than a danger — a rough twenty-four hours, a rest day, and back on the trail. But on a trek the stakes are higher than at home: dehydration at altitude is a real problem, a lodge toilet at 4 am in sub-zero temperatures is nobody's idea of a holiday, and a schedule with a flight at the end has little room for lost days.

Most of it is preventable with a few boring habits, and most of the rest is treatable with a small kit and some knowledge. This guide covers both.

This article is general information for trip planning, not medical advice. Antibiotics and other prescription medicines should be used as directed by the doctor who prescribed them.

Why Trekkers Get Sick

Almost all stomach illness on a trek is spread the same way: microbes from human or animal faeces reach your mouth, by water, food or hands.

• Hands. The most underrated route. Door handles, banknotes, shared serving spoons, your own boots — and then a biscuit.
• Water. Tap and stream water throughout Nepal should be treated, however clear it looks.
• Food. Salads washed in untreated water, food that has sat lukewarm, and meat carried up the trail for days without refrigeration.
• The city. A large share of infections are picked up in Kathmandu or Pokhara in the first few days — the celebratory pre-trek dinner — and surface two or three days into the walk.
• Other trekkers. Viral stomach bugs pass quickly through a crowded lodge.

Lodge kitchens on the main routes are generally careful, and freshly cooked dal bhat is among the safest meals you can eat anywhere. See food on the trail and teahouse trekking explained.

Prevention That Works

1. Clean your hands before every meal and snack. Soap and water where there is any; sanitiser otherwise. This single habit prevents more illness than everything else on the list.
2. Drink only treated water. Boiled, filtered, or treated with tablets or ultraviolet light. Brush your teeth with it too. See drinking water while trekking.
3. Eat food that is cooked to order and served hot. Dal bhat, fried rice, noodle soup, boiled potatoes.
4. Go vegetarian above the road head. Meat is carried up unrefrigerated, sometimes for days. Animals are not slaughtered in many high Buddhist valleys.
5. Skip salads and unpeeled fruit on the trail. Peel it yourself or leave it.
6. Be careful in the city. Eat at busy places, avoid buffets that have been sitting, and go easy the night before the trek.
7. Use your own water bottle, and do not share bottles, cutlery or snacks from the bag with sticky fingers.
8. Keep fingernails short.

What Kind of Illness Is It?

You do not need a laboratory to make a reasonable guess. Onset and pattern tell you most of what you need.

The useful distinction is between sudden and watery, which is usually bacterial or viral and treated with fluids and perhaps a stand-by antibiotic, and slow, gassy and persistent, which suggests a parasite and needs a different drug.

Treatment, Step by Step

1. Rehydrate first, always. Mix oral rehydration salts with treated water and sip continuously — a glass after every loose stool, more if you are vomiting. Take small sips if you are nauseous. This matters more than any tablet.
2. Tell your guide. They will adjust the day and keep an eye on you.
3. Rest. A day in the lodge now often saves three later.
4. Eat when you can. Plain rice, soup, boiled potatoes, toast, dal. There is no need to starve; avoid fried and spicy food and dairy for a day or two.
5. Loperamide for travel days only. It slows the gut and buys a few hours' control for a walk or a bus ride. It treats the symptom, not the cause. Do not use it if you have a fever or blood in the stool.
6. The stand-by antibiotic, if you have one. For moderate or severe illness — many stools a day, fever, or unable to function — take it as your doctor instructed. Azithromycin is the usual choice for South Asia because resistance to older antibiotics is widespread. Most people improve within a day.
7. Anti-sickness medication if vomiting is stopping you keeping fluids down.
8. Suspect a parasite if it began gradually, with bloating and sulphurous burps, or if it drags on past a week. That needs a different medicine and, ideally, a stool test in Kathmandu or Pokhara.

If you run out of rehydration sachets, a workable substitute is six level teaspoons of sugar and half a level teaspoon of salt dissolved in one litre of treated water. Nepali pharmacies and many trail shops sell rehydration salts under the name Jeevan Jal.

Why It Matters More at Altitude

• You are already short of fluid. Fast breathing in dry air loses a surprising amount of water. Diarrhoea on top of that dehydrates you quickly.
• Dehydration feels like altitude sickness. Headache, nausea, fatigue and dizziness belong to both, and it becomes hard to know which you have.
• Nausea and vomiting are also symptoms of altitude sickness — so do not assume it is only your stomach.
• A depleted body acclimatises poorly and feels the cold more.
• Medicines stack up. Acetazolamide is a diuretic; anti-inflammatory painkillers are hard on dehydrated kidneys.

The rule: do not gain sleeping altitude while you have active diarrhoea or vomiting. Hold where you are, rehydrate, and go up when you are drinking and eating normally.

If headache and nausea persist once you are rehydrated, treat it as altitude sickness — see our altitude guide.

When to Descend or Get Medical Help

• Blood or mucus in the stool.
• A temperature above 38.5°C, or shaking chills.
• Unable to keep fluids down for more than twelve hours.
• Signs of dehydration: very little dark urine, dizziness on standing, a dry mouth, confusion.
• Severe or localised abdominal pain, especially low on the right side.
• No improvement within 48 hours of starting an antibiotic.
• Symptoms lasting more than a week.
• Any stomach illness in a child, an older trekker, a diabetic or someone with a serious medical condition — act sooner.

Any of these means going down, and usually out, to a clinic. From most main routes that means a walk to a road or airstrip, or a helicopter if you cannot walk — which is what insurance is for. See travel insurance for trekking in Nepal.

Recovery After the Trek

• Appetite and energy take a few days to return. Eat plainly and often.
• Milk may disagree with you for a week or two. A gut infection can temporarily reduce your ability to digest lactose; it comes back.
• Finish any antibiotic course as prescribed.
• Probiotics are harmless and may help a little; the evidence is modest.
• Loose stools for more than two weeks after you get home need a stool test. Giardia and cyclospora are both common in travellers returning from Nepal, both are easily treated, and neither goes away reliably on its own.
• Bloating and irregular bowels can linger for weeks after a bad infection, even when tests are clear. It usually settles; see your doctor if it does not.
• Tell your doctor where you have been. It changes which tests they order.

More on the weeks afterwards is in illness after a Nepal trek and post-trek recovery.

We Provide This Service: Pre- and Post-Trek Health Support

Green Compass Treks provides health support before, during and after every trek, and stomach illness is the problem our guides manage most often.

• Before the trek: a briefing on food, water and hand hygiene, advice on where to eat in Kathmandu and Pokhara, and a check that you are carrying rehydration salts and any stand-by medication your doctor prescribed.
• On the trek: lodges chosen for clean kitchens, safe drinking water arranged each day, and guides who carry rehydration salts and know when a rest day is the right call.
• Flexible itineraries, with a spare day where possible so an upset stomach does not cost you the trek.
• If it is serious: descent, evacuation through your insurer, and admission to a clinic in Kathmandu or Pokhara.
• After the trek: a clinic appointment and stool test arranged before you fly, if symptoms have not cleared — far easier in Nepal, where the laboratories see these infections daily, than at home.

We do not prescribe or supply antibiotics; bring any stand-by treatment from your own doctor. For anything else, ask us.