Stomach sore is a term used to describe a condition in which the lining of the stomach becomes irritated and inflamed, often causing pain and discomfort. The medical term for this condition is gastritis or peptic ULCER disease, and the crossword solution for this is 'ULCER'. Ulcers are caused by a variety of factors, including stress, certain medications, and bacterial infections. Treatment for stomach sores typically involves lifestyle changes, such as reducing stress, avoiding certain foods, and taking medications to reduce inflammation.