Constipation occurs when bowel movements become tough or infrequent. Nearly everyone will experience constipation at one point or another. The frequency of a bowel movement will depend on each person. Most people will have one three times a day, while others have them only twice or three times a week. With things like this everyone has a different "normal", depending on their size and diet.
However, as a rule of thumb, you shouldn’t go more than three days without a bowel movement. Some of the causes of constipation include a lack of fiber, reduced water consumption, or not being active enough. If you have constipation, you may experience trouble passing a bowel movement and hard or small stools.
If you think you might be suffering from this, it is important to seek adequate treatment. First, you should increase your water intake by two extra glasses of water per day; secondly, you may eat fruits and vegetables rich in fiber to get things moving again.