Various types of potatoes. A staple food, or simply a staple, is a food that is eaten routinely and in such quantities that it constitutes a dominant portion of a standard diet for a given people, supplying a large fraction of energy needs and generally forming a significant proportion of the intake of other nutrients as well.
Constipation is defined medically as fewer than three stools per week and severe constipation as less than one stool per week. Constipation usually is caused by the slow movement of stool through the colon.
One of the leading causes of dark stools is chronic heartburn. Heartburn involves the regurgitation of acids from the stomach into the esophagus, typically resulting in a burning pressure or pain from the breast bone up the throat. The pain is usually worse with bending, lying down, or after eating.