“Just like you, they're affected by shifts to your sleep schedule, changes in diet, exposure to new microbes, and excess stress,” explains Raja Dhir, the co-CEO of the microbiome company Seed Health. How these microbes respond to those shifts can lead to overactive bowels.

Increased bowel movements on vacation, often called "Traveler's Diarrhea," are typically caused by changes in diet, hydration, and exposure to new bacteria. When you travel, you likely consume more fiber-rich fruits, spicy foods, or oily restaurant meals than you do at home, which can stimulate the digestive tract. Furthermore, even in developed countries, your gut is exposed to local strains of E. coli or other microbes that your body isn't used to, leading to a mild "flush" as your immune system reacts. Stress and caffeine from travel days can also speed up "gastric emptying." To manage this, stick to bottled water in high-risk areas, avoid "room temperature" buffet food, and try to maintain some consistency in your eating schedule. If the frequency is accompanied by pain or fever, it may be a more serious infection requiring medical attention.