(See also Overview of Foreign Bodies in the GI Tract.)
A bezoar is a tightly packed collection of partially digested or undigested material that is unable to exit the stomach. Gastric bezoars are usually rare and can occur in all age groups. They often occur in patients with behavior disorder or abnormal gastric emptying and also after gastric surgery. Many bezoars are asymptomatic, but some cause symptoms. Some bezoars can be dissolved chemically, others removed endoscopically, and some require surgery.
Bezoars are classified according to their composition:
Phytobezoars (vegetable—most common)
Pharmacobezoars (drugs; particularly common with sucralfate and aluminum hydroxide gel)
Diospyrobezoars, a subset of phytobezoars (excessive intake of persimmon; occur most often in regions where the fruit is grown)
Other (variety of other substances including tissue paper and polystyrene foam products such as cups)
Trichobezoars, which can weigh several kilograms, most commonly occur in young females with psychiatric disorders who chew and swallow their own hair.
Phytobezoars are the most common form of bezoar. They often occur in adult patients as a postoperative complication after gastric bypass or partial gastrectomy, especially when partial gastrectomy is accompanied by vagotomy. Delayed gastric emptying due to diabetes mellitus or other systemic illness increases the risk of gastric bezoar formation. Other predisposing factors include hypochlorhydria, diminished antral motility, and incomplete mastication; these factors are more common among the elderly, who are thus at higher risk of bezoar formation.
Gastric bezoars are usually asymptomatic. When symptoms are present, the most common include postprandial fullness, abdominal pain, nausea, vomiting, anorexia, and weight loss.
Bezoars are detectable as a mass lesion on imaging studies (eg, x-ray, ultrasound, CT) that are often done to evaluate the patient's nonspecific upper GI symptoms. The findings may be mistaken for tumors.
Upper endoscopy is usually done to confirm the diagnosis. On endoscopy, bezoars have an unmistakable irregular surface and may range in color from yellow-green to gray-black. An endoscopic biopsy that yields hair or plant material is diagnostic.
The optimal therapeutic intervention is controversial because randomized controlled trials comparing different options have not been done.
Chemical dissolution using agents such as cola and cellulase can be done for patients with mild symptoms. Cellulase dosage is 3 to 5 g dissolved in 300 to 500 mL of water; this is taken over the course of a day for 2 to 5 days. Metoclopramide 10 mg po is often given as an adjunct to promote gastric motility. Enzymatic digestion using papain is no longer recommended.
Endoscopic removal is indicated for patients who have bezoars that fail to dissolve, moderate to severe symptoms due to large bezoars, or both. If initial diagnosis is made by endoscopy, removal can be attempted at that time. Fragmentation with forceps, wire snare, jet spray, or even laser (1) may break up bezoars, allowing them to pass or be extracted.
Surgery is reserved for cases in which chemical dissolution and endoscopic intervention cannot be done or have failed or for patients with complications.
Persimmon fruit bezoars are usually hard and difficult to treat because persimmons contain the tannin shibuol, which polymerizes in the stomach.