Fact v fiction: holiday constipation, bloating and diarrhoea explained

Going on holiday is supposed to be a break from everyday life, but your gut doesn’t always get the memo. Whether it’s unexpected diarrhoea, struggling to go at all, or feeling unusually bloated after a flight, many people notice changes in their digestion when they travel. 

It’s easy to blame one thing - stress, unfamiliar food, or even holiday indulgence - but the reality is that it usually comes down to a combination of different factors. This is because travel can affect the digestive system in several ways, from disrupting your routine and sleep schedule to changing what you eat, drink, and do each day.  

So, what really happens to your gut when you go away? Here’s a look at some common beliefs about pooing on holiday and what the evidence actually tells us. 

Fiction: Changes in bowel habits while travelling can affect almost anyone 

Stress and anxiety can influence digestion through the gut-brain axis, which is the communication network linking the digestive system and nervous system. For some people, feeling nervous about travelling may contribute to symptoms such as diarrhoea, stomach discomfort, or constipation. 

However, anxiety is only one piece of the puzzle. Travel often involves changes to eating patterns, meal timings, hydration, physical activity, and sleep - all of which can affect normal bowel function. 

Tip: Find your personal way of managing stress before going away and try to keep some parts of your routine consistent whilst you’re there. Eating meals at similar times and staying active can help provide a sense of normality for your mind, body and your gut. 

Fiction: Food related illness is one possible cause; but it isn’t the only explanation 

Traveller’s diarrhoea is commonly associated with exposure to unfamiliar bacteria, viruses, or parasites through food and water. However, not every episode of holiday diarrhoea is caused by food poisoning. 

Changes in diet alone can affect bowel habits. Eating richer foods, drinking more alcohol, trying unfamiliar dishes, or significantly increasing food intake may all alter digestive function. 

Travel-related stress, disrupted sleep, and changes to the gut microbiome may also contribute. In many cases, symptoms result from a combination of factors rather than one clearly identifiable cause. 

Tip: Introduce new dishes gradually rather than changing your entire diet overnight and stay well hydrated if you do experience looser stools. 

Fiction: Flying can have noticeable effects on the digestive system 

Aircraft cabins are pressurised, but not to the sea-level conditions we’re used to. As cabin pressure changes during flight, gas trapped inside the digestive tract can expand. This is one reason many people feel bloated or experience increased wind while flying - the effect is usually temporary, but it can cause discomfort, particularly on longer journeys.  

And on top of this, spending long periods sitting down and changes to meal timing while travelling may also contribute to feelings of digestive sluggishness. 

Tip: Drink plenty of water before and during a flight, avoid too many fizzy drinks, and take short walks around the cabin to help reduce digestive discomfort. 

Fiction: Sleep and digestion are more closely linked than many people realise 

Whether it’s jet lag, an early flight, a different time zone, or simply sleeping in an unfamiliar environment, disrupted sleep is common during travel. 

Research suggests that sleep and gut function influence one another through several biological pathways. Poor sleep can affect digestive motility, appetite regulation, and hormone production, while digestive discomfort can also make it harder to sleep well. 

This relationship helps explain why some people notice changes in bowel habits after long-haul travel or periods of disrupted sleep. A successful holiday definitely involves flexibility, but maintaining some consistency in sleep patterns may help support digestive comfort while away. 

Tip: If you're travelling across time zones, trying to get some natural daylight exposure on arrival (and especially in the mornings) may help your body adapt more smoothly. 

Fact: Hot weather can indirectly influence bowel function 

When temperatures rise the body loses more fluid through sweating and, if those fluids are not replaced, dehydration can occur. Hot weather can also influence appetite, physical activity levels, and daily routines, all of which may contribute to changes in bowel habits. 

Hydration plays an important role in normal digestion because water helps keep stools soft and supports movement through the digestive tract. This means that if fluid intake is too low, especially in hotter environments, stools may become harder and more difficult to pass. 

So, while sunshine itself isn't directly affecting the gut, the effects of heat on the body can influence digestion 

Tip: In hot weather, make a conscious effort to drink fluids regularly throughout the day, particularly if you're spending long periods outdoors or being more active than usual. 

Fiction: Constipation is one of the most common digestive complaints during travel 

Holiday diarrhoea often receives more attention, but many travellers experience the opposite problem. 

The gut likes consistency, which is why even relatively small changes to daily habits can disrupt the body’s normal digestive rhythm. For example, long journeys, reduced physical activity, dehydration, altered meal schedules, and even avoiding going to the loo in public toilets can all contribute to constipation. 

So, for many people, not being able to open their bowels may be just as likely - if not more likely - than diarrhoea when travelling, because of all the disruption to daily norms.  

Tip: Keep moving, stay hydrated, keep eating fibre… and don’t ignore the urge to go, even if it comes unexpectedly! Let your bowels find their flow.  

Summary