The human digestive system is extremely powerful, digesting and absorbing all the nutrients in food and drinks into the bloodstream within hours. Food has to pass through 6 meters of the digestive tract and then is temporarily stored in the colon to absorb water. Normally, the food residue will be dissolved out of the body after 1-2 days. Depending on the food, age and daily activity, there are usually three bowel movements a day to three bowel movements a week. The drier the stool in the colon, the more difficult it is to pass. Normal stools are not too dry or excessively loose and should not be extracted by straining. Modern busy lifestyle habits are probably the most common cause of constipation. Inadequate dietary fiber intake, inadequate water intake, lack of exercise, and failure to go to the stool in a timely manner when the bowel movement occurs are some of the causes. Chronic constipation may also be a symptom of other serious diseases such as irritable bowel syndrome, colorectal cancer, diabetes, Parkinson’s disease, depression, multiple sclerosis, or hypothyroidism. Bowel movements often vary with age and environment. For example, formula-fed children have drier stools than breast-fed children and are more likely to become constipated. Some children also become constipated when they first start school because they are afraid to ask about their bowel movements. Older adults, especially those who are sedentary, are more likely to become constipated. Other medications that can cause constipation include narcotics, diuretics, iron, antacids, and some antihypertensives, antiepileptics, and depressants.