Merck Manual

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Zubair Malik

, MD, Temple University Hospital

Last full review/revision Feb 2020| Content last modified Feb 2020
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Bezoars are tightly packed collections of partially digested or undigested material that can become stuck in the stomach or intestines.

  • 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 ¾ of an inch (about 2 centimeters) in diameter are rarely able to pass out of the stomach because of the narrow opening (pyloric sphincter) that the stomach's contents must pass through to enter the first segment of the small intestine (duodenum).

There are several types of bezoars. Bezoars are classified according to what they are made of:

  • Phytobezoars are most common and are made of undigestible fruit and vegetable material such as fiber, peels, and seeds.

  • Diospyrobezoars, a kind of phytobezoar, are made of fruits called persimmons.

  • Trichobezoars are made of partially digested hair.

  • Pharmacobezoars are made of hardened blocks of drugs (such as antacids).

  • Lactobezoars are made of milk protein and can occur in infants who are fed milk.

Bezoars can also be made of a variety of other substances including tissue paper and polystyrene foam products (such as cups).

Risk factors for bezoars

Food or other materials can collect in anyone, including children, but are more likely to collect in people who have certain risk factors.

General risk factors include

Risk factors more common in older people include

  • No teeth

  • Poorly fitting dentures

  • Not chewing food completely

  • Having a low level of stomach acid (hypochlorhydria)

Trichobezoars most commonly occur in young females who have mental health disorders who chew and swallow their own hair.


Most bezoars do not completely block the digestive tract and thus cause no symptoms. However, people may feel very full after eating a normal-sized meal and may have nausea, vomiting, and pain. People may also lose their appetite and lose weight.

Complications of bezoars

Sometimes bezoars disrupt the lining of the gastrointestinal tract and cause bleeding, which may appear in the stool (see Gastrointestinal Bleeding).

If bezoars are partially or completely obstructing the stomach, the small intestine, or, rarely, the large intestine, they may cause cramps, bloating, loss of appetite, nausea, and vomiting (see Intestinal Obstruction). Sometimes bezoars cause intussusception (where one segment of the intestine slides into another, much like the parts of a telescope) and can block the intestines. If not treated, intussusception sometimes causes part of the intestinal tissue to die.

Bezoars can also rarely cause a perforation of the digestive tract. A perforation allows food, digestive juices, or intestinal contents including stool to leak into the abdomen. Such leakage is a medical emergency because it can cause peritonitis (inflammation of the peritoneal [abdominal] cavity).


  • Imaging tests

  • Endoscopy

Often, a bezoar can be seen on imaging tests, such as x-rays, computed tomography (CT), and ultrasonography, of the abdomen.

Usually, endoscopy (a visual examination of the digestive tract using a flexible tube called an endoscope) is done to confirm the diagnosis of a bezoar and to exclude a tumor as the cause. During the endoscopy, doctors may remove a piece of a bezoar and examine it under a microscope to see what it is made of, such as hair or plant material. Doctors may try to break the bezoar into pieces and remove it during endoscopy.


  • Measures to dissolve the bezoar

  • Endoscopy

  • Sometimes surgery

To help break down and dissolve a bezoar, a doctor may prescribe cola or cellulase for people who have mild symptoms. Cellulase is dissolved in water and taken by mouth for 2 to 5 days. Doctors may also give another drug taken by mouth called metoclopramide. This drug stimulates the movement of contents through the stomach and intestines.

If the bezoar does not dissolve or if people have moderate to severe symptoms, doctors can try to remove the bezoar by doing endoscopy.

During endoscopy, doctors sometimes use forceps, a laser, or other instruments to break bezoars into pieces so that they can pass through or be removed more easily.

Bezoars that are hard as rocks (such as those made of persimmons) usually need to be removed surgically.

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