Pathophysiological and clinical aspects of the diagnosis and treatment of bezoars
Executive Summary
Bezoars are intraluminal conglomerates of indigestible materials that accumulate within the gastrointestinal (GI) tract. While historically viewed as medicinal or magical substances, they are modernly recognized as potentially life-threatening pathological entities. This document synthesizes current clinical data regarding their classification, diagnostic protocols, and multi-modal therapeutic approaches.
Key Takeaways:
Classification: Bezoars are categorized by composition, with phytobezoars (plant-based) being the most prevalent. Other types include trichobezoars (hair), pharmacobezoars (medication), and lactobezoars (milk).
Pathogenesis: Previous gastric surgery (vagotomy or gastrectomy) is the primary risk factor, occurring in 20-93% of diagnosed cases.
Diagnosis: Contrast-enhanced computed tomography (CT) is the gold standard for diagnosis, offering high sensitivity (90%) by revealing a characteristic "mottled appearance" with air bubbles.
Management: Treatment ranges from chemical dissolution (notably using Coca-Cola®) and endoscopic fragmentation to laparoscopic or open surgery for complicated cases involving obstruction or perforation.
Taxonomy and Pathophysiology
Bezoars are classified based on the specific indigestible materials from which they are formed.
Phytobezoars
Derived from the Greek phyto (plant), these are the most common bezoars. They consist of vegetable or fruit fibers (e.g., celery, skins, seeds).
Persimmon Bezoars: A particularly challenging subtype caused by the consumption of the genus Diospyros. High concentrations of tannin in unripe persimmons polymerize upon contact with gastric acid, forming an adhesive matrix that binds plant fibers into a hard mass.
Pharmacobezoars
Formed from conglomerates of medications (pharmako).
Common Culprits: Antacids, Kayexalate, and bulk-forming laxatives (psyllium).
Mechanism: Insoluble carriers in enteric-coated or slow-release medications (such as cellulose acetate in verapamil or nifedipine) can aggregate in the GI tract. Dehydration and gastroparetic effects from antipsychotics can further facilitate formation.
Trichobezoars
Composed of ingested hair (tricha), these are typically found in young women with psychiatric conditions such as trichotillomania (compulsive hair pulling) and trichophagia (compulsive hair eating).
Rapunzel Syndrome: A rare condition where a gastric trichobezoar extends a "tail" into the small intestine or ascending colon.
Lactobezoars
Undigested masses of milk formula and mucus found in infants.
Risk Factors: Prematurity and low birth weight are significant factors. High caloric and protein concentrations in synthetic formulas may exceed the digestive enzyme capacity of neonates.
Epidemiology and Predisposing Factors
Prevalence
Bezoars are infrequent, discovered in less than 0.5% of upper GI endoscopies. However, they represent a significant cause of acute intestinal obstruction (ileus), accounting for 0.4% to 4.8% of all such cases.
Risk Factors
The formation of bezoars is rarely spontaneous and is usually linked to specific physiological or behavioral triggers:
Gastric Surgery: Procedures such as vagotomy, pyloroplasty, or partial gastrectomy reduce gastric acidity and motility while widening the outlet, allowing large, undigested boluses to enter the small intestine.
Dietary Habits: Excessive consumption of high-fiber foods, poor mastication (often due to dentures in the elderly), and rapid swallowing.
Systemic Conditions: Diabetes mellitus, hypothyroidism, and renal failure can alter GI motility.
Diagnostic Modalities
Diagnosis relies on a combination of clinical presentation and advanced imaging.
Clinical Presentation
Symptoms range from mild abdominal discomfort, fullness, and anorexia to severe complications:
GI Bleeding: Ulcers or mucosal necrosis caused by intraluminal pressure.
Acute Abdomen: Vomiting, distension, hypotension, and shock in cases of complete obstruction or perforation.
Imaging Standards
Therapeutic Approaches
Treatment is determined by the bezoar's location, size, and composition.
1. Chemical Dissolution
Primarily used for gastric phytobezoars.
Coca-Cola® (CC): A first-line treatment with a reported resolution rate of up to 91%. Protocols involve gastric lavage with 3 to 4.8 liters over 12–24 hours.
Enzymatic Agents: Cellulase, papain, and pancreatin can degrade plant fibers, though they may cause gastric ulcers or electrolyte imbalances.
2. Endoscopic Fragmentation
For gastric bezoars resistant to dissolution, mechanical disintegration is performed using:
Biopsy forceps and polypectomy snares.
Lithotripters and argon plasma coagulation.
Laser devices (Nd:YAG).
3. Surgical Intervention
Surgery is mandatory for intestinal bezoars, failed conservative treatments, or life-threatening complications (ischemia/perforation).
Laparotomy: The traditional approach involving enterotomy (incising the bowel) to remove the mass.
Laparoscopy: A minimally invasive alternative offering better visualization and faster recovery, though restricted by the presence of dilated intestinal loops or extensive adhesions.
LECS: Laparoscopic and Endoscopic Cooperative Surgery is an emerging combined technique for large gastric bezoars.
"Milking" Technique: Attempting to manually advance the bezoar through the ileocecal valve. This is controversial due to risks of serosa laceration and postoperative adhesions.
Case Series Highlights
A study of nine patients (mean age 67.3) over five years provided the following insights:
Demographics: Included 4 females and 5 males; 55% had a history of gastric surgery.
Location: The majority of phytobezoars were discovered in the small intestine, specifically within 1.5 meters of the ileocecal valve.
Outcomes:
One gastric grape phytobezoar was successfully treated with 3L of Coca-Cola®.
A "double phytobezoar" (gastric and ileal) required both laparotomy and endoscopic fragmentation.
A massive ileal bezoar (75x8 cm) caused perforation, requiring intestinal resection and primary anastomosis.
Concluding Remarks
As global populations age, bezoars are increasingly recognized as a cause of GI complications. While modern imaging (CT) and endoscopic advances have improved diagnostic accuracy, surgical intervention—particularly laparotomy—remains the definitive treatment for complicated cases. Future research into the chemical synthesis of bezoars is necessary to develop better preventative strategies.
