sentences:  Altered blood bears resemblance to coffee grounds (as the iron in the blood is oxidized) and, when this matter is identified, the term coffee-ground vomiting is used.Bile can enter the vomit during subsequent heaves due to duodenal contraction if the vomiting is severe.Fecal vomiting is often a consequence of intestinal obstruction or a gastrocolic fistula and is treated as a warning sign of this potentially serious problem ("signum mali ominis").