Traveller's Diarrhoea in Istanbul: Timeline and Warning Signs

Your digestive system has just cancelled the rest of today's plans and possibly tomorrow's, and the question you want answered is a simple one: how long is this going to last, and should I be worried?

The short version is that the ordinary kind settles by itself over a small number of days, gets gradually better rather than gradually worse, and needs fluids more than it needs anything else. The part that matters more is the second half of the answer — the features that mean this is not the ordinary kind, and that it is time to have someone look at you rather than wait another night.

What "Traveller's Diarrhoea" Actually Refers To

The phrase covers the common digestive upset that starts during or just after a trip. It is not a diagnosis in itself, and it is not a comment on any particular country's food. It is what happens when the bacteria your gut is used to meet a week of different water, different cooking, different oils, different meal times and considerably more of everything than you would eat at home.

Istanbul adds two ordinary aggravators: it is hot for much of the year, which means you are already losing fluid before anything goes wrong, and it is a walking city, which means you are a long way from your bathroom when it does.

Why it started, and why it so often waits until the second or third day of a trip, is a separate question with its own answer, and it is not what you need at this moment.

The Usual Shape of the First Day

The beginning is usually abrupt. People describe it as fine at lunch and unmistakably not fine by the evening. Along with the obvious symptom there is often cramping, a sense of urgency, nausea, tiredness out of proportion to everything else, and a general feeling of having been unplugged.

This first stretch is typically the worst of it, and it is also the point at which the most fluid is lost, which is why so much of the sensible advice for day one is about drinking rather than about treating. If you are going to feel wretched, this is the day.

Plans for the following morning should be considered flexible at this stage rather than cancelled outright. What you are watching for overnight is direction of travel.

Days Two and Three: Direction Matters More Than Intensity

By the second day, the ordinary version has usually turned a corner. It is not gone — it is less frequent, less urgent, and the cramping has eased. Appetite starts to return in a cautious, suspicious sort of way. Tiredness typically outlasts everything else by a day or two.

The useful thing to track over this period is not how bad you feel at any single moment, which fluctuates, but whether the overall line is going the right way. Something that is clearly milder than yesterday is behaving as expected. Something that is the same as yesterday, or worse, is not, and that is a reason to ask for an opinion regardless of how many days have passed.

This is also the point where dehydration, rather than the original upset, becomes the thing that actually makes people feel terrible — particularly on a hot day, and particularly if someone has been avoiding drinking in the hope of reducing the trips to the bathroom. That instinct is understandable and it works against you.

When It Goes On Longer Than It Should

If things are still going on after several days with no clear improvement, the situation has changed category. It is no longer a question of waiting it out, and it should be assessed rather than endured — not because something serious is necessarily happening, but because a prolonged course is exactly the situation where the cause is worth establishing rather than assuming.

The same applies to anything that improves and then relapses, and to anything that lingers at a low level for longer than the rest of the trip.

In some of these cases a doctor may want a sample tested before deciding what to do, which is a normal step rather than an alarming one and is explained in why a doctor may ask for a lab test before deciding.

The Signs That Change the Answer

Regardless of which day you are on, some features mean the question is no longer "how long" but "who can look at me". Ask for an assessment if any of the following is part of the picture:

• Blood in what you are passing, or stools that are black and tarry.
• Being unable to keep fluids down at all, because vomiting is bringing everything straight back.
• Severe or constant abdominal pain, as opposed to cramping that comes and goes.
• A fever that is high enough to frighten you, or shaking chills.
• Signs that you are drying out: passing very little urine, very dark urine, dizziness on standing, a dry mouth, or unusual drowsiness and confusion.
• Symptoms that are getting steadily worse rather than better, or that are still going strong after several days.
• Any of this in a traveller who is already dealing with another significant health condition.

Who Should Ask Sooner Rather Than Later

Some travellers have less room to wait and see, because fluid loss affects them faster or because they have something else going on at the same time.

• Young children, who can become dehydrated strikingly quickly — see a doctor visit for a child at your hotel.
• Older travellers, particularly anyone taking regular medication — see hotel doctor visits for older travellers.
• Anyone who is pregnant — see pregnant travellers feeling unwell in Istanbul.
• Anyone managing a long-term condition such as diabetes or kidney disease, or taking medicines that are affected by dehydration or by missed doses — see chronic conditions on holiday.
• Anyone whose immune system is suppressed for any reason.

If you are in one of these groups, the sensible threshold for asking is lower, and asking early is not an overreaction.

Fluids Are the Part Within Your Control

While you are deciding, the one thing that is unambiguously useful is replacing what you are losing. Fluid, and not only water, is what keeps an unpleasant few days from turning into something that needs more attention.

What is appropriate to drink, and whether any rehydration product or medicine is suitable for your situation, is a question for a pharmacist or a doctor rather than for an article — that answer depends on your age, your other conditions and what else you take. Turkish pharmacies are plentiful, easy to find, and used to advising visitors.

One thing worth stating plainly: medicines that stop the symptom are not always the right choice, and in some situations they are specifically unhelpful. That decision is not a guess to be made from a phone screen in a hotel room.

What a Doctor Can Do Where You Are Staying

A visit for this is not a dramatic event. A doctor comes to your hotel, Airbnb or residence, asks what you have eaten and drunk and when it started, examines you, and forms a view of how dehydrated you actually are — which is usually the question that matters most and the one that is hardest to judge from the inside.

From there the picture is straightforward. Most people need an assessment, reassurance about what they are dealing with, something to make the next day survivable, and clear instructions about what would mean getting back in touch. Some need rehydration support. A small number need a test, and a smaller number need a hospital. English-speaking doctors and nurses attend the visit, which matters more than usual when the conversation involves describing symptoms you would rather not describe in a second language.

The practical advantage in this particular illness is obvious: crossing Istanbul in traffic is close to the last thing anybody in this condition wants to do.

When It Is an Emergency

A small number of situations should not wait for any of the above.

Severe or constant abdominal pain, vomiting blood, black tarry stools, a stiff neck with a high fever, loss of consciousness or new confusion, or signs of severe dehydration such as being unable to stand or to stay awake are emergencies.

Call 112 or go to the nearest hospital emergency department rather than arranging a visit.

Related Services

• Food Poisoning Treatment in Istanbul — assessment and treatment of digestive illness at your accommodation address.
• Hotel Doctor in Istanbul — an in-person assessment at any hour, for symptoms that are not clearly settling.
• Laboratory & Diagnostic Services — testing arranged around a visit when a doctor wants to establish a cause before deciding.

If your stomach has taken over your trip and you are not sure whether to wait another night, describe what has been happening and your hotel name on WhatsApp — and if any of the emergency signs above apply, call 112 instead.