Review of the diagnosis and management of gastrointestinal bezoars
Executive Summary
Gastrointestinal bezoars are rare but clinically significant indigestible masses trapped within the digestive system, most commonly the stomach. They are classified into four primary types based on their composition: phytobezoars (plant materials), trichobezoars (hair), pharmacobezoars (medications), and lactobezoars (milk protein). While generally infrequent, with a prevalence of less than 0.5% in endoscopic examinations, they can lead to severe complications including gastric ulcers (observed in 64.5% of cases), gastrointestinal bleeding, and small bowel obstruction.
A critical finding in current management is the efficacy of Coca-Cola® administration as a first-line treatment for phytobezoars, achieving resolution in over 90% of reported cases. However, persimmon phytobezoars (diospyrobezoars) present a unique challenge due to their high tannin content and exceptionally hard consistency, making them frequently resistant to chemical dissolution and requiring endoscopic or surgical intervention.
Classification and Etiology of Bezoars
Bezoars are categorized by the materials that constitute the mass. The etiology varies significantly across these classifications:
Phytobezoars: The most common type, formed from indigestible plant fibers, skins, and seeds (e.g., celery, pumpkins, grape skins, and persimmons). They contain cellulose, hemicellulose, lignin, and tannins.
Trichobezoars: Composed of ingested hair, these are almost exclusively found in young females with psychiatric comorbidities such as trichotillomania (hair-pulling) and trichophagia (hair-eating). A rare extension into the small intestine is known as Rapunzel syndrome.
Pharmacobezoars: Result from the conglomeration of medications. Common culprits include bulk-forming laxatives (psyllium, guar gum) and extended-release drug vehicles (e.g., nifedipine or verapamil) coated in cellulose acetate.
Lactobezoars: Composed of undigested milk and mucus, found almost entirely in milk-fed infants. Prevalence has decreased recently, likely due to improved synthetic milk compositions.
Other Materials: Rare bezoars have been documented containing plastic, metal, parasitic worms, and toilet paper.
Prevalence and Patient Susceptibility
The incidence of bezoars is variable but generally low across clinical studies:
Gastric Prevalence: Reported between 0.068% and 0.43% of all endoscopies.
Small Intestine Prevalence: Bezoars account for 0.4% to 4.8% of all intestinal obstruction cases.
Geographic Variation: Persimmon phytobezoars are more prevalent in regions with high persimmon consumption, such as Japan, South Korea, Israel, Spain, Turkey, and the Southeastern United States.
Predisposing Risk Factors
Bezoar formation is typically associated with delayed gastric emptying and impaired motility. Key risk factors identified include:
Prior Gastric Surgery: 35.5% of patients in the reviewed series had histories of partial gastrectomy, vagotomy, or pyloroplasty.
Underlying Conditions: Diabetes mellitus (9.7% of patients), peptic ulcer disease, hypothyroidism, and Crohn’s disease.
Demographics: Excluding trichobezoars, bezoars are most common in elderly individuals (median age 74 in the study series).
Specialized Analysis of Persimmon Phytobezoars (Diospyrobezoars)
Persimmon phytobezoars are uniquely resilient due to the polymerization of persimmon tannin (shibuol) upon contact with stomach acid.
Microstructure and Elemental Composition
Ultrastructural analysis via scanning electron microscopy (SEM) reveals a distinct two-part structure:
Exterior Surface: A high-density, continuous layer (20-50 µm thick) composed of aggregated microgranules. This layer provides resistance to mechanical and chemical forces.
Inner Core: A lower-density interior featuring sheet-like structures with unoccupied spaces between them.
Elemental analysis using energy-dispersive X-ray spectroscopy (EDX) shows significant differences between the surface and the core:
Note: The high concentration of iron on the surface suggests that iron(III) tannate is responsible for the characteristic black or dark-brown color of persimmon bezoars.
Manifestations and Diagnosis
Clinical Presentation
Bezoars may be asymptomatic or present with diverse symptoms. In a study of 31 patients, initial presentations included:
Pain: 35.5%
Gastrointestinal Bleeding: Manifesting as bloody/tarry stool (16.1%) or hematemesis (9.7%).
Other Symptoms: Abdominal fullness, discomfort, nausea, anemia, and difficulty swallowing.
Diagnostic Modalities
Endoscopy: The primary tool for detecting gastric bezoars (74.2% of cases in the series). It allows for direct visualization of the mass and associated complications like gastric ulcers (present in 64.5% of patients).
Computed Tomography (CT): Useful for detecting both gastric and small intestinal bezoars. Bezoars appear as ovoid occupational masses with a mottled appearance due to internal air bubbles. CT is essential for identifying the site of obstruction and the presence of multiple bezoars.
Management and Treatment Strategies
Chemical Dissolution with Coca-Cola®
Coca-Cola® is considered the primary choice for phytobezoar treatment because it is safe, inexpensive, and highly effective (91.3% success rate).
Mechanism: Dissolution is believed to be aided by sodium bicarbonate (mucolytic effect), carbonic/phosphoric acid (acidifying effect), and carbon dioxide bubbles that penetrate microscopic pores in the bezoar.
Efficacy of Varieties: In vitro research indicates that Coca-Cola Zero® (16.1% dissolubility) and regular Coca-Cola® (18.5% dissolubility) have nearly equal phytolytic activity.
Protocols: Common methods include nasogastric lavage (3000 mL over 12 hours) or oral intake (e.g., 500-1000 mL daily for several weeks).
Enzymatic Therapy
Cellulase: Used to degrade cellulose; however, it is often unavailable as a prescription medication and may require high doses found only in specific dietary supplements.
Papain: Extracted from papaya, it has been used historically (e.g., meat tenderizers). However, it carries risks of gastric ulceration and esophageal perforation, and its efficacy in dietary supplement forms is limited.
Interventional and Surgical Options
Endoscopic Fragmentation: Utilizes biopsy forceps, snares, or basket catheters to break the mass. For harder persimmon bezoars, multiple sessions or specialized tools like an electrosurgical knife or "bezoaratom" may be required.
Surgical Removal: Necessary for small intestinal bezoars causing ileus or for gastric bezoars refractory to other treatments. Laparoscopic surgery is increasingly preferred over open laparotomy due to its minimally invasive nature.
Prokinetic Agents: Medications like itopride or metoclopramide may assist in resolving soft bezoars by enhancing gastric motility.
Conclusion
The management of gastrointestinal bezoars requires a tailored approach based on the bezoar type and patient stability. While Coca-Cola® has revolutionized the treatment of most phytobezoars, the unique chemical and structural properties of persimmon phytobezoars—specifically their dense, tannin-rich exterior—often necessitate more aggressive endoscopic or surgical interventions. Prompt diagnosis via endoscopy and CT remains critical to preventing severe complications like pressure-induced gastric necrosis and intestinal ileus.
