Bezoars are balls of undigested materials, insoluble fiber, and undissolved medicines that resist the action of digestive enzymes in the stomach. Bezoars are the result of a lack of stomach hydrochloric acid secretion, without which medicine like sulfa drugs, iron, and antacid tablets may not dissolve. They may also be caused by poor stomach emptying.

Bezoars in humans cause the feeling of fullness, pain, nausea, and vomiting, and they reduce or prevent stomach emptying. Treatment may include avoidance of fibrous foods such as apples, berries, Brussels sprouts, beans, and sauerkraut, as well as changes in any medication being taken. Bezoars may also form in animals' stomachs. In ancient Persian medicine, bezoars were used as an antidote to poison.

Simin B. Vaghefi