NEW YORK – Your bathroom habits are pretty regular at home, but as soon as you leave for a trip, constipation hits.

If this scenario describes you, you are not alone.

Scientists do not know exactly how many people experience difficulties with bowel movements on vacation, a phenomenon sometimes called traveller’s constipation.

But Dr Satish Rao, a professor of medicine at Augusta University in Georgia who studies constipation, said that in his experience, it is pretty common – affecting perhaps one in three people.

Having a bowel movement anywhere from two or three times a week to three times a day is normal, Dr Rao said.

But if you are going much less often, or if your stools are lumpy and difficult to pass, you are probably constipated.

If your trip involves a long flight, you can often blame dehydration and immobility, said Dr Madhulika Varma, chief of colorectal surgery at UCSF Medical Center.

Dry airplane air can be dehydrating, and some travellers may consume fewer drinks on flights to avoid going to the toilet frequently, she said.

If you become dehydrated, your body may pull more fluids from your colon, leaving behind a hard, lumpy stool that can be challenging and painful to pass.

Sitting still for a long time, she said, can slow the muscle contractions that move food through your digestive system.

A departure from your sleep routine can also be a culprit.

Changing time zones can disrupt your circadian rhythm, the internal clock that regulates sleep and digestion, Dr Rao said. “If you’re not waking up at your usual time, your colon gets confused.”

This can happen even if you do not cross time zones, said gastroenterologist Erin Toto at Penn Medicine. Sometimes, slight changes from your typical eating and sleeping routine can throw things out of whack.

The best way to prevent constipation is to be proactive with diet, sleep and hydration, Dr Toto said.

A few days before your trip, make sure you are getting enough fluids, especially if you are heading to high altitudes or hot climates, said gastroenterologist Samita Garg at Cleveland Clinic.

Dr Rao cautioned against bubbly drinks such as seltzers or sodas. While they can help with hydration, they may make you feel gassy and bloated.

Try to limit how much alcohol you drink too. This can cause or worsen dehydration.

Schedule permitting, Dr Garg said, you could try shifting your sleep schedule towards the time zone you are visiting.

Once there, exercise – even just 15 minutes of walking can stimulate your colon.

Try to avoid going overboard on fatty meats, fried foods or foods rich in dairy, she added. These take longer to break down in the gut.

She recommended the “three F’s”: fluid, fibre and fruit (and vegetables).

Prioritising fibre is key. Recommendations vary from person to person, but most people should aim to consume at least 25g of fibre a day, Dr Varma said.

Soluble fibre supplements, such as psyllium, tend to work well for constipation, she added.

But be sure to drink them with water, which makes your stool softer and easier to pass. And it is always a good idea to check with your doctor before taking any supplements.

Fermented foods such as sauerkraut, kimchi and yogurt can also help keep your gut microbiome healthy, which aids digestion, Dr Rao said. And drinking coffee can stimulate the urge to go.

Over-the-counter laxatives can help, but not all are best for travel.

Dr Toto recommended polyethylene glycol (Miralax), which tends to cause less cramping and diarrhoea than stimulant laxatives like bisacodyl (Dulcolax).

If it has been a few days and you have not had a bowel movement, do not panic, Dr Toto said. “It’s definitely a myth that you need to poop every day,” she added.

Dr Rao recommended calling a doctor if it has been three times as long as what is normal for you. If you usually go every other day, you can probably go around a week without a bowel movement.

No matter what, experts say, call a doctor if there is blood in your stool or if you are in extreme pain.

And if you are not feeling the urge to go, Dr Varma said it is best to avoid pushing or straining too much. This can cause a host of other problems, including haemorrhoids. NYTIMES