Opium preparation is an opioid. An opioid is sometimes called a narcotic.Opium is derived from the seed pod of a poppy plant. It works by increasing smooth muscle tone and decreasing fluid secretions in the intestines. This slows the movement of bowel matter through the intestines.pium is derived from the seed pod of a poppy plant. It works by increasing smooth muscle tone and decreasing fluid secretions in the intestines. This slows the movement of bowel matter through the intestines.