A bezoar is a solid mass of indigestible material that accumulates in the digestive tract, most often in the stomach. These masses form when substances like plant fiber, hair, or medication residue collect over time instead of passing through normally. Bezoars range from small, harmless clumps to large obstructions that require medical intervention.
The Four Types of Bezoars
Bezoars are classified by what they’re made of, and each type has distinct causes and risk profiles.
Phytobezoars are the most common type. They form from indigestible plant material, particularly foods high in fiber, cellulose, and compounds called tannins. Persimmons are the single most frequent culprit, especially dried astringent varieties. The tannins in persimmons react with stomach acid and cause plant fibers and proteins to clump together into a solid mass. Other foods linked to phytobezoars include celery, pumpkin, grape skins, prunes, and raisins.
Trichobezoars are hairballs that form in the stomach. Human hair resists digestive enzymes and has a smooth surface that prevents it from moving through the gut, so swallowed hair accumulates over months or years. Trichobezoars are nearly always found in young women and girls with two related behavioral conditions: a compulsive urge to pull out their own hair (trichotillomania) and the habit of swallowing it. About 80% of people with compulsive hair-pulling also have anxiety or depression, and the behavior can appear alongside obsessive-compulsive disorder, borderline personality disorder, or intellectual disabilities.
Pharmacobezoars form from medications or their outer shells. Extended-release drugs are a common cause because they’re designed to pass through the gut slowly, sometimes inside a hard cellulose casing that doesn’t dissolve at all. Bulk-forming laxatives and fiber supplements can also clump together in the stomach due to their water-absorbing properties. Some extended-release tablets pass through the body as intact “ghost tablets” visible in stool, which is normal, but in people with narrowed sections of the digestive tract, these shells can pile up and cause a blockage.
Lactobezoars are the rarest type, occurring almost exclusively in infants. They form from undigested milk protein, typically in premature or low-birth-weight babies whose digestive systems aren’t fully developed. Contributing factors include formula with high protein or fat content, concentrated calorie formulas, dehydration, and medications that slow stomach emptying.
Who Is Most at Risk
Anything that slows the stomach’s ability to empty its contents raises the risk. People with gastroparesis, a condition where the stomach muscles don’t contract properly, are particularly vulnerable because food sits in the stomach far longer than it should. Previous stomach surgeries can also create the conditions for bezoar formation by altering how food moves through the digestive tract or by creating narrowed passages where material gets trapped.
Diet plays a major role in phytobezoar risk. Eating large quantities of high-fiber or high-tannin foods, particularly persimmons, on a regular basis increases the chance of a mass forming. People who have difficulty chewing their food thoroughly, including those with poor dentition or who eat very quickly, may also be at higher risk since larger food particles are harder for the stomach to break down.
Symptoms to Recognize
Many gastric bezoars cause no symptoms at all and are discovered incidentally during imaging for other reasons. When symptoms do appear, they tend to be vague and easy to mistake for other digestive problems: a feeling of fullness after eating, abdominal pain, nausea, vomiting, loss of appetite, and unexplained weight loss.
Larger bezoars or those that move into the small intestine can cause more serious problems. A bezoar that blocks the intestine creates a surgical emergency, with severe cramping pain, inability to pass gas or stool, and persistent vomiting. In rare cases, a bezoar pressing against the stomach wall for a prolonged period can cause ulceration or even perforation, where a hole develops in the wall of the digestive tract.
How Bezoars Are Found
Because the symptoms overlap with so many other conditions, bezoars are often detected on imaging studies ordered to investigate general upper digestive complaints. They appear as a mass on X-rays, ultrasounds, or CT scans. Endoscopy, where a flexible camera is passed down the throat into the stomach, provides the clearest view and has the added advantage of allowing treatment at the same time as diagnosis.
Rapunzel Syndrome
In extreme cases, a trichobezoar can grow so large that it fills the stomach and extends a long tail of matted hair down into the small intestine. This is called Rapunzel syndrome, after the fairy tale character. It’s rare but dangerous, because the trailing hair can cause blockages, ulcers, or perforations at multiple points along the digestive tract. Rapunzel syndrome almost always requires surgical removal rather than less invasive approaches.
Treatment Options
Treatment depends on the type and size of the bezoar. For phytobezoars, one of the more surprising approaches involves cola. Gastric lavage with cola, or simply drinking it in large quantities, can dissolve plant-based bezoars because the carbonation and acidity help break down the fiber matrix. In one study, three liters of cola achieved complete dissolution in about 24% of cases and partial dissolution in the remaining 76%. Bezoars made from persimmon fiber were the most stubborn and resisted complete breakdown with cola alone, often needing additional treatment afterward.
Endoscopic removal is the most common intervention for bezoars that don’t dissolve on their own. Doctors use a range of tools passed through the endoscope to fragment the mass: grasping forceps to tear the surface apart, wire snares to cut through the material, net baskets to capture loose pieces, and sometimes high-frequency electrical cutting for tougher masses like hairballs. Hair doesn’t dissolve chemically but can’t withstand high temperatures, so applying brief electrical heat through the endoscope helps break it apart before a snare cuts through the weakened sections.
For very large bezoars, particularly dense trichobezoars or cases of Rapunzel syndrome, surgery is often the only option. The mass is removed through an incision in the stomach wall. Recovery from this surgery typically takes several days in the hospital, and for trichobezoars, addressing the underlying hair-pulling behavior through psychiatric care is essential to prevent recurrence.
Lactobezoars in infants are usually managed by temporarily stopping oral feeding and providing fluids intravenously, allowing the milk mass to break down on its own. Adjusting the formula composition afterward helps prevent new bezoars from forming.