Masses of undigestible materials can get stuck in the stomach.
Most bezoars cause no symptoms.
The diagnosis is based on x-rays and other imaging tests and on a visual examination of the digestive tract using endoscopy.
Most bezoars need to be broken up into pieces with instruments or with swallowed agents or removed using an endoscope or surgically.

The stomach is a common collection site for hardened, partially digested or undigested masses of material called bezoars. Bezoars cannot pass through narrow openings or spaces and thus may get stuck in the digestive tract. Bezoars accumulate most often in the stomach but sometimes elsewhere in the digestive tract. Bezoars larger than