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.
Black or red stools that aren't caused by orange, purple, or red foods can indicate internal bleeding somewhere in the gastrointestinal tract. Stool that contains blood from the upper digestive tract is black, tarry, has a distinctive odor, and is known as melena.