A watery rice gruel and a production method of a watery rice gruel, which can be taken even by patients such as cancer patients who have experienced an extreme loss of appetite, stimulate the hypothalamus in the brains of these patients and enhance their appetite as well as keeping the physical homeostasis of these patients normal.By placing dark-roasted unpolished rice 4, black rice 6 and adlay 7 in water 9 and boiling, the bitter taste and rich aroma of the dark-roasted unpolished rice 4 is imparted to the watery rice gruel obtained by boiling. The water rice gruel promotes intestinal movement in the patient, while the rich aromatic component dissolved into the watery rice gruel promotes the discharge of gas that has accumulated in the stomach and intestinal tract of the patient, thereby eliminating the feeling of distention of the stomach and intestines.