Apple is a fruit that can both cause and relieve ulcers. The acids found in apples, if eaten before going to bed, might aggravate the stomach lining while you’re lying on a hard surface–thus worsening an ulcer. However, apples also contain a lot of fiber which promotes healthy bowels and helps to alleviate problems with ulcers. So make sure to eat your apple after hours or on a soft surface for optimal results!..