Lots of things can cause constipation: poor diet (especially not getting enough fiber and fluids), stress, travel, and even certain medications and digestive conditions like diabetes can all prevent your colon from absorbing enough water from the food you eat so it can be easily eliminated.
Drinking more water and adding fiber-rich foods to your diet can ease constipation, but so can movement. Physical activity stimulates the muscles in your intestine, so they can move your waste along more easily. Yoga has an added benefit in relieving constipation. Certain yoga poses—particularly twists and poses that put pressure on the abdomen—gently massage your digestive tract, encouraging it to move stool along. In fact, a 2015 study found that yoga can ease symptoms of Irritable Bowel Syndrome, which often includes bouts of constipation.