A bezoar is a tightly packed collection of partially digested or undigested material that most commonly occurs in the stomach. Gastric bezoars can occur in all age groups and often occur in patients with behavior disorders, abnormal gastric emptying, or altered gastrointestinal anatomy. Many bezoars are asymptomatic, but some cause symptoms. Some bezoars can be dissolved chemically, others require endoscopic removal, and some even require surgery.
(See also Overview of Foreign Bodies in the Gastrointestinal Tract.)
Bezoars are classified according to their composition:
Phytobezoars (most common) are composed of indigestible fruit and vegetable matter such as fiber, peels, and seeds.
Trichobezoars are composed of hair.
Pharmacobezoars are concretions of ingested medications (particularly common with sucralfate and aluminum hydroxide gel).
Diospyrobezoars, a subset of phytobezoars, result from excessive intake of persimmon and occur most often in regions where the fruit is grown.
Lactobezoars are composed of milk protein.
Other bezoars are composed of a variety of other substances including tissue paper and polystyrene foam products such as cups.
Etiology of Bezoars
Phytobezoars can occur in adult patients as a postoperative complication after gastric bypass or partial gastrectomy, especially when partial gastrectomy is accompanied by vagotomy.
Trichobezoars most commonly occur in young females with psychiatric disorders who chew and swallow their own hair.
Lactobezoars can occur in milk-fed infants.
Delayed gastric emptying due to diabetes mellitus, mixed connective tissue disease, other systemic illness, or drugs increases the risk of gastric bezoar formation.
Other predisposing factors include hypochlorhydria, diminished antral motility, and incomplete mastication; these factors are more common among older people, who are thus at higher risk of bezoar formation.
Symptoms and Signs of Bezoars
Gastric bezoars are usually asymptomatic. When symptoms are present, the most common include postprandial fullness, abdominal pain, nausea, vomiting, anorexia, and weight loss.
Ускладнення
Rarely, bezoars cause serious complications including
Gastric outlet obstruction
Gastrointestinal bleeding secondary to ulceration
Diagnosis of Bezoars
Endoscopy
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 gastrointestinal 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.
Treatment of Bezoars
Chemical dissolution
Endoscopic removal
Sometimes surgery
The optimal therapeutic intervention is controversial because randomized controlled trials comparing different options have not been done. Sometimes, combination therapy is required.
Chemical dissolution using agents such as cola and cellulase can be done for patients with mild symptoms (1). 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 orally 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, argon plasma coagulation, or even laser (2) 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, for patients with complications, or for patients with intestinal bezoars.
Persimmon fruit bezoars are usually hard and difficult to treat because persimmons contain the tannin shibuol, which polymerizes in the stomach. They do not respond well to chemical dissolution and usually require endoscopic or surgical removal.
Довідкові матеріали щодо лікування
1. Iwamuro M, Okada H, Matsueda K, et al: Review of the diagnosis and management of gastrointestinal bezoars. World J Gastrointest Endosc 7(4):336–345, 2015. doi: 10.4253/wjge.v7.i4.336
2. Mao Y, Qiu H, Liu Q, et al: Endoscopic lithotripsy for gastric bezoars by Nd:YAG laser-ignited mini-explosive technique. Lasers Med Sci 29:1237–1240, 2014. doi: 10.1007/s10103-013-1512-1
