Understanding Bezoars and Their Composition
A bezoar is a solid mass of indigestible or poorly digested material that gets trapped in the gastrointestinal (GI) tract, most commonly the stomach [1.9.4, 1.11.3]. While rare in the general population, their incidence is higher in patients with predisposing factors like previous gastric surgery, poor stomach motility (gastroparesis), and certain dietary habits [1.8.3, 1.9.3]. Bezoars are classified based on their primary component [1.6.3]:
- Phytobezoars: The most common type, composed of indigestible plant fibers such as cellulose, hemicellulose, and lignin. Foods like persimmons, celery, prunes, and raisins are often implicated [1.8.1].
- Trichobezoars: Formed from ingested hair and are most frequently seen in young women with psychiatric conditions like trichotillomania [1.9.4].
- Pharmacobezoars: Concretions of medications, often from bulk-forming laxatives or improperly dissolved extended-release tablets [1.8.3, 1.9.3].
- Lactobezoars: Typically found in infants and are made of concentrated milk formula [1.6.4].
The composition of a bezoar is a critical factor in determining the most effective treatment approach, particularly when considering chemical dissolution, also known as enzymatic therapy [1.3.5].
Chemical Dissolution: The Primary Pharmacological Approach
The main strategy for medicinally dissolving a bezoar is through chemical dissolution, or 'drug lithotripsy' [1.2.1]. This non-invasive approach involves administering agents that can break down the bezoar's structure, allowing it to soften, shrink, and pass through the GI tract naturally [1.8.1]. This method is most successful for phytobezoars due to their organic nature [1.2.1].
Key Agents Used for Bezoar Dissolution
Several agents have been studied and used with varying degrees of success. The choice often depends on the bezoar type and the availability of the agent.
Coca-Cola Lavage
Perhaps the most widely reported and studied first-line treatment for phytobezoars is Coca-Cola [1.2.2]. Its effectiveness is attributed to several mechanisms. The combination of carbonic and phosphoric acid creates a low pH environment similar to gastric acid, which aids in fiber digestion [1.6.5]. Additionally, the sodium bicarbonate content has a mucolytic effect, and the CO2 bubbles are thought to penetrate the bezoar's surface, helping to break it apart [1.6.1, 1.6.5].
Systematic reviews have shown that Coca-Cola administration, either via nasogastric lavage (up to 3 liters over 12 hours) or by drinking, can lead to complete phytobezoar resolution in a high percentage of cases, either alone or combined with endoscopic methods [1.4.2, 1.6.1]. Studies have also indicated that sugar-free versions like Coca-Cola Zero are equally effective [1.4.2]. However, its efficacy is significantly lower for harder diospyrobezoars (from persimmons), which are often resistant to chemical dissolution alone [1.4.2, 1.6.3].
Enzymatic Therapy: Cellulase and Papain
Cellulase: Since phytobezoars are made of plant matter rich in cellulose, the enzyme cellulase is a logical treatment choice. It works by cleaving the glycosidic bonds in cellulose, directly breaking down the bezoar's main structural component [1.3.2]. Cellulase has been used successfully, often dissolved in water and taken orally over several days [1.7.3]. However, a major limitation is that a standardized, pure form of cellulase is not readily available as a prescription medication in many countries; it is typically found in over-the-counter dietary supplements combined with other enzymes [1.4.1, 1.4.2]. Some case series report high success rates when combining cellulase tablets with Coca-Cola ingestion [1.4.1].
Papain: This proteolytic enzyme, derived from papaya, functions by hydrolyzing proteins within the bezoar matrix [1.5.2]. In the past, it was a component of some meat tenderizers and was used for bezoar dissolution [1.4.2]. While some studies showed it to be effective, its use has fallen out of favor due to potential adverse effects, including gastric ulceration and esophageal perforation [1.4.2, 1.5.5]. Furthermore, in vitro studies have shown its dissolvability to be less potent than Coca-Cola [1.4.2].
Other Agents and Prokinetics
- Pancreatic Enzymes: In some cases, a cocktail of pancreatic enzymes (containing protease, amylase, and lipase) dissolved in Coca-Cola has been used successfully, especially for esophageal bezoars [1.2.4].
- Sodium Bicarbonate: For enteral feed bezoars, which can solidify in acidic environments, sodium bicarbonate solution has been shown to be an effective dissolving agent [1.2.5].
- Prokinetic Agents: Medications like metoclopramide and erythromycin do not dissolve the bezoar directly but can be used as adjuncts [1.7.4]. By promoting gastric motility and enhancing stomach contractions, they may help break down softer bezoars and facilitate their passage out of the stomach [1.7.1].
Comparison of Dissolution Agents
| Agent | Mechanism of Action | Target Bezoar | Efficacy & Notes |
|---|---|---|---|
| Coca-Cola | Acidification (phosphoric/carbonic acid), mucolytic effect (sodium bicarbonate), mechanical action (CO2 bubbles) [1.6.5]. | Primarily Phytobezoars [1.2.2]. | Widely considered an effective first-line therapy [1.2.2]. Success rates are high, though lower for hard persimmon bezoars [1.6.3]. |
| Cellulase | Enzymatically breaks down cellulose, a key component of plant fiber [1.3.2]. | Phytobezoars [1.4.5]. | Effective, especially in combination with Coca-Cola [1.4.1]. Not readily available as a pure, standardized prescription [1.4.2]. |
| Papain | Proteolytic enzyme that hydrolyzes proteins [1.5.2]. | Phytobezoars [1.5.1]. | Largely fallen out of favor due to the risk of gastric and esophageal injury and unproven efficacy in modern studies [1.4.2, 1.5.5]. |
| Pancreatic Enzymes | Proteolytic, amylolytic, and lipolytic action [1.2.4]. | Esophageal and feed bezoars [1.2.4]. | Used successfully in combination with Coca-Cola in some case reports [1.2.4]. |
When Medication Fails: Other Treatment Modalities
It is crucial to note that chemical dissolution is not always successful or appropriate. Trichobezoars, for example, are resistant to enzymatic degradation and almost always require invasive removal [1.8.3]. If medication fails, or if the patient presents with complications like severe pain or bowel obstruction, other treatments are necessary [1.2.1].
- Endoscopic Fragmentation: A common next step involves using an endoscope with various tools—such as forceps, snares, or even lasers—to physically break the bezoar into smaller pieces that can either be removed or passed naturally [1.2.1, 1.10.2]. Combining Coca-Cola lavage with endoscopy can soften the bezoar, making fragmentation easier [1.6.3].
- Surgery: Laparoscopic or open surgery is the definitive treatment and is reserved for cases where other methods have failed, for very large or hard bezoars (like some trichobezoars or diospyrobezoars), or when complications like perforation or complete bowel obstruction occur [1.2.1, 1.11.4].
Conclusion
For the most common type of bezoar, the phytobezoar, several pharmacological options exist for dissolution. Coca-Cola has emerged as a simple, cost-effective, and widely available first-line treatment [1.2.2]. The enzyme cellulase is also an effective agent, particularly when combined with Coca-Cola, though its availability can be a challenge [1.4.1]. While agents like papain have historical significance, they are rarely used today due to safety concerns [1.4.2]. For bezoars that are resistant to chemical breakdown or for other types like trichobezoars, more invasive methods such as endoscopic fragmentation or surgery are required for successful removal [1.8.3].
Disclaimer: This article is for informational purposes only. Always consult with a qualified healthcare professional for diagnosis and treatment of any medical condition.
