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.
Ask a Doctor Online Now! Any blood passing through the stomach will be colored black, due to oxidation of hemoglobin iron by stomach acid. Some stomach acid may appear in the duodenum, so any bleeding arising from the duodenum or above, will cause black, tarry, foul smelling stool that sticks to the toilet. Possible causes of black stool from bleeding include: 1  Stomach or duodenal inflammation (gastritis), erosion, or ulcer due to alcohol, smoking, strong spices, or infection with H. pylori bacteria. 2  Stomach or duodenal cancer.  Esophageal varices due to liver cirrhosis (often in alcoholics), or portal hypertension.