Eating copious amounts of dairy products can cause constipation, according to WebMD. Other common causes of constipation include inadequate intake of water or fiber, inadequate activity and lack of exercise, stress and disruption of the regular routine while traveling.
Constipation can also be caused by an individual's resistance to have a bowel movement, such as when they resist the urge to evacuate the bowels due to the pain caused by hemorrhoids.
Certain conditions and diseases can also cause constipation. For instance, hypothyroidism, Parkinson's disease and other neurological conditions such as multiple sclerosis, depression and irritable bowel syndrome, can be culprits behind constipation. Eating disorders, pregnancy and colon cancer can also cause constipation.
Some underlying causes of constipation are more ominous. Constipation can be an indicator of a serious underlying medical problem and may require medical intervention to diagnose and treat. In some instances, constipation may be caused by colonic inertia, which is a condition that causes the colon to contract poorly, with the result being that stool is retained for longer periods of time. Another cause of constipation that may require medical intervention is an obstruction in the bowel, a condition that is marked by excessive straining to expel waste from the body.