Constipation occurs when stool passes through the large intestine too slowly. Some lifestyle habits that can cause constipation include changing diet, exercise, or travel routines, ignoring the urge to have a bowel movement, stress, eating a low-fiber diet, not drinking enough liquids, taking calcium or iron supplements, or taking painkillers. Constipation may be present if you have three or fewer bowel movements per week or hard, dry, painful stools that are difficult to pass. Following a varied diet high in fiber, drinking plenty of fluids, exercising regularly, and using fiber supplements if needed can help relieve mild constipation for most people.