Medically reviewed by Dr. Ponlawat Pitsuwan, Physician, Takecare Clinic Phuket. Last reviewed: September 2026.
Diarrhoea is common in Phuket, but I pay particular attention to how long it has lasted and who is affected. Young children, older adults and people with long-term conditions become dehydrated faster, and diarrhoea lasting more than two weeks needs a different approach from a short holiday upset.
Diarrhoea is a symptom rather than a diagnosis, and on holiday it has many possible sources: a gut infection, a change in diet, a heavy night of drinking, a new medicine or simply the heat. We see it in holidaymakers on their first day and in long-stay visitors six weeks into a Phuket winter, and the questions we ask differ for each. Families add another layer, because young children dehydrate faster than adults and show it differently. This page explains how we sort one kind of diarrhoea from another and what each needs.
Acute, persistent or chronic: why the calendar matters
The World Health Organization defines diarrhoea as three or more loose or watery stools in 24 hours. How long it has lasted is the first thing that shapes our thinking.
Acute diarrhoea lasts less than 14 days and is almost always an infection, viral (norovirus, or rotavirus in babies) or bacterial. The specific holiday syndromes, sudden illness after one meal and the diarrhoea that builds in the first week abroad, are covered on our food poisoning treatment and traveller’s diarrhoea treatment pages.
Persistent diarrhoea runs from 14 to 30 days. Parasites such as Giardia become more likely, as do the after-effects of an earlier infection: post-infectious irritable bowel syndrome (IBS), or temporary lactose intolerance while the gut lining heals. Chronic diarrhoea, beyond four weeks, is rarely holiday-related; IBS, coeliac disease, inflammatory bowel disease and an overactive thyroid are more typical, and it deserves proper investigation.
Non-infectious triggers include alcohol, magnesium supplements, metformin and, above all, a recent antibiotic course, which can occasionally let Clostridioides difficile, a bacterium causing more severe diarrhoea, take hold.
How dehydrated are you?
Dehydration, not the diarrhoea itself, is what makes people seriously ill, and Phuket’s heat speeds it up through sweat. At the clinic we check pulse and blood pressure lying and standing, how quickly colour returns to a pressed fingertip (capillary refill) and, in children, weight and alertness. You can check yourself with the signs below.
| Level | Adults | Babies and children | What to do |
|---|---|---|---|
| Mild | Thirst, darker urine, dry mouth | Thirsty, slightly fewer wet nappies | Oral rehydration salts at home |
| Moderate | Dizzy on standing, headache, little urine | No tears, sunken eyes, irritable or unusually quiet | See a doctor the same day |
| Severe | Confusion, racing pulse, no urine for 12 hours | Drowsy, floppy, cold mottled hands, sunken soft spot | Emergency care, call 1669 |
Oral rehydration, done properly
Oral rehydration salts (ORS) replace water together with sodium, potassium and glucose; the glucose helps the gut absorb the salt, and water follows. Sachets are sold in every Phuket pharmacy. Dissolve one in exactly the volume of bottled water on the packet, since a stronger mix can worsen diarrhoea. WHO guidance for each loose stool is 50 to 100 ml for children under 2, 100 to 200 ml for children aged 2 to 10, and as much as they want for older children and adults, on top of normal drinking. If no sachets are available, six level teaspoons of sugar and half a level teaspoon of salt in one litre of clean water is a reasonable stopgap.
Juice and soft drinks are a poor substitute because the sugar draws water into the bowel. Keep eating bland foods such as rice, noodle soup and bananas, and continue breast or formula feeds for babies. Over-the-counter loperamide can reduce stool frequency in adults, but not with blood or fever, and not in young children. If vomiting stops you drinking, intravenous fluids restore you within hours, as our page on IV drip therapy in Phuket explains.
When a test is worth doing
Most acute diarrhoea needs no tests, because the result arrives after you are better. We test when it changes what we do: blood or mucus in the stool, fever of 38.5°C or above, moderate or severe dehydration, symptoms beyond seven days, a recent antibiotic course or hospital stay, a weakened immune system, or an outbreak among a group.
Stool tests include a culture or multiplex PCR panel that detects bacteria, viruses and parasites, microscopy for parasites, and a C. difficile toxin test after antibiotics. For chronic symptoms, faecal calprotectin, a marker of bowel inflammation, helps separate IBS from inflammatory bowel disease. Our blood tests in Phuket cover complete blood count, electrolytes, kidney function and CRP, an inflammation marker, with thyroid and coeliac tests for longer-running cases. Common results are ready the same day.
Diarrhoea in babies and children
Children lose fluid quickly and cannot always tell you they feel dizzy or thirsty, so watch the nappies, tears and energy level. Offer ORS in small, frequent amounts, a teaspoon or syringe every minute or two if they are also vomiting, since tiny volumes stay down better than a full cup. Avoid juice and fizzy drinks, and do not give loperamide to young children. Babies under six months, and any child who is drowsy, refusing fluids or passing blood, should be seen promptly. Keep children out of the kids’ club or pool until 48 hours after the last episode, which also protects other families.
The Phuket angle: short trips and long stays
Short-stay visitors mostly have acute infections that settle in days. Long-stay visitors, retirees wintering on the island and remote workers are more likely to develop persistent diarrhoea from Giardia, often from untreated water, or the lingering bowel changes of post-infectious IBS. Heat and alcohol compound fluid losses in both groups, and a course of antibiotics started for something else, such as a skin or ear infection, is a frequent and overlooked trigger.
When to see a doctor
Diarrhoea that follows antibiotics or a hospital stay needs a doctor, and older adults, pregnant women and anyone with diabetes, kidney disease, heart failure or a weakened immune system should come in earlier than others. A change in bowel habit lasting more than a few weeks, particularly after the age of 50, needs investigation even if you feel well.
Prevention and early detection
Soap-and-water hand washing before eating and after the toilet prevents more diarrhoea than any tablet. Drink sealed bottled or filtered water and, on long stays, never untreated tap or well water, a common route for Giardia. Rotavirus vaccine, routine for infants in many countries, protects babies from the most dehydrating childhood infection, so check your child’s record. Early detection has two sides: start ORS at the first loose stool, and do not ignore a bowel change that persists after you get home.
How to be seen at Takecare Clinic
We are open around the clock at the Bangtao (Cherngtalay) clinic, the Kata-Karon clinic and the Patong clinic. Walk in at any hour, or message us on WhatsApp first so we can prepare, and you can call the clinic on +66 81 718 9080. Walk-in patients are usually seen within minutes; our walk-in doctor in Phuket page sets out the process.
For a sick child or an adult too unwell to travel, a doctor hotel visit in Phuket brings the assessment, medicines and fluids to your room, 24/7. Paperwork is covered too: direct billing with most travel insurers, or receipts, medical reports and itemised invoices if you claim yourself. We confirm the price on WhatsApp before your visit.
Related services and treatments
If burning pain in the upper stomach is your main problem rather than loose stools, see our gastritis treatment page. For everything else, from dengue to ear infections, visit our conditions we treat page.
Summary
Diarrhoea on holiday is usually a short infection that needs fluids and time. Duration guides the thinking: under two weeks is almost always infection, two to four weeks raises parasites and post-infectious change, and beyond four weeks needs a proper work-up. Check yourself for dehydration, use ORS correctly, test only when it changes management, and act early for babies, older adults and anyone with blood or fever.
“Watch for signs of dehydration such as dark urine, dizziness or a dry mouth. In children, fewer wet nappies is an early warning to seek help.”
Dr. Ponlawat Pitsuwan, Physician, Takecare Clinic Phuket
Frequently asked questions
Does travel insurance pay for a diarrhoea visit, and how is the cost worked out?
Acute illness on holiday is covered by most travel insurance policies, but conditions and excesses vary, so check yours. We direct-bill most travel insurers and otherwise give you a receipt, a medical report and an itemised invoice. The cost depends on the consultation plus any medicines, tests or drip you need, and we confirm the price on WhatsApp before your visit.
How long should diarrhoea last before I stop waiting and see someone?
Most acute diarrhoea improves within two to four days and is gone within a week. Adults who are not improving after seven days, or who have blood, fever or dizziness at any point, should be seen. For babies and young children the threshold is lower, so come in the same day if they are drinking poorly or seem unusually quiet or drowsy.
Can I walk in with my child, or should I book a slot?
Walk straight in; there is no need to book at any of our three clinics, day or night. Children who look dehydrated are seen first. Bring any medicines you have already given and, if you can, note roughly how many loose stools and wet nappies there have been, which helps the doctor judge hydration quickly.
Could a doctor come to our villa to check a child with diarrhoea?
Yes. Our doctors visit hotels, villas and condos anywhere in Phuket, 24/7. The visiting doctor examines your child, checks hydration, shows you how to give oral rehydration in small amounts and can give intravenous fluids if needed. If hospital care is required, we arrange the referral directly.
Will I need a stool sample?
Most people do not. A stool test is worth doing when there is blood, a high fever, significant dehydration, symptoms beyond a week, a recent course of antibiotics or a weakened immune system. We provide a sample pot and our on-site laboratory runs common tests the same day, so results can change your treatment before you leave Phuket.
Why do I still have loose stools weeks after a stomach bug?
After a gut infection the bowel lining and its nerves can stay sensitive for weeks, a pattern called post-infectious irritable bowel syndrome, and some people become temporarily intolerant of lactose. A parasite such as Giardia is another possibility, particularly after drinking untreated water. Diarrhoea beyond two weeks deserves stool tests rather than more waiting.
Sources
The World Health Organization diarrhoeal disease fact sheet gives the definition and oral rehydration guidance used on this page. The NHS page on diarrhoea and vomiting in adults and children covers dehydration signs and when to get help. MedlinePlus has a clear overview of acute and chronic diarrhoea.
diarrhoea, diarrhea, acute diarrhoea, persistent diarrhoea, chronic diarrhoea, dehydration, gastroenteritis, norovirus, rotavirus, Giardia, Cyclospora, Clostridioides difficile, post-infectious irritable bowel syndrome, lactose intolerance, coeliac disease, oral rehydration salts, loperamide, stool PCR, faecal calprotectin, CRP, WHO, NHS, MedlinePlus, Bangtao, Kata, Karon, Patong, Takecare Clinic Phuket, Dr. Ponlawat Pitsuwan
This page is general health information and not a substitute for a medical consultation.