A bezoar is a solid mass of indigestible or partially digested materials that accumulates within the gastrointestinal tract. These masses vary in size and composition, potentially obstructing normal digestive function. Once thought to have magical properties, bezoars are now recognized as a medical condition that can affect anyone. This article explores how bezoars form, their common types, symptoms, diagnosis, and treatment.
Formation and Location
Bezoars typically form when indigestible materials accumulate and clump together in the gastrointestinal tract. This process often begins with the ingestion of substances that resist digestion, which then coalesce into a solid mass. The exact formation mechanism depends on the specific material involved.
These masses are most commonly found in the stomach, known as gastric bezoars. However, bezoars can also form or move into other parts of the gastrointestinal tract, such as the small or large intestines. In the large intestine, a bezoar is sometimes called a fecalith. Conditions that slow gastric emptying or alter gastrointestinal anatomy, like previous gastric surgeries, can increase the risk of bezoar formation.
Common Types
Bezoars are classified by their primary composition. Phytobezoars are the most common type, accounting for about 40% of reported cases. They consist of indigestible plant materials like fibers, peels, and seeds from fruits and vegetables, especially persimmons. A specific subset, diospyrobezoars, forms from persimmons when stomach acid reacts with tannins in the fruit, causing them to coagulate.
Trichobezoars are composed of ingested hair and food particles. These can sometimes grow to a significant size. They are often associated with psychiatric conditions like trichotillomania (hair pulling) and trichotillophagia (eating hair), and are more common in adolescent or young adult females.
Lactobezoars are masses of milk protein that form in the stomachs of infants, especially premature or low-birth-weight babies consuming high-calorie formulas. They typically occur due to immature gastrointestinal systems and factors like dehydration. Pharmacobezoars are concretions of undissolved medications or their carriers that accumulate in the digestive tract. Other unusual materials like plastic, tissue paper, or parasitic worms have also been reported to form foreign body bezoars.
Signs and Symptoms
A bezoar may not always cause noticeable symptoms, especially if it is small and does not obstruct the digestive tract. When symptoms do occur, they vary widely based on the bezoar’s size, location, and whether it causes an obstruction. Common indicators include abdominal pain, often described as epigastric discomfort.
Nausea and vomiting are common, sometimes leading to loss of appetite and unintended weight loss. A feeling of fullness after consuming only a small amount of food is also a frequent complaint. In some instances, a physical examination may reveal a palpable mass in the abdomen. If a bezoar causes a partial or complete blockage, more severe symptoms like bloating, cramps, and an inability to pass stool or gas can develop.
Diagnosis and Treatment
Diagnosing a bezoar typically involves medical history, physical examination, and imaging studies. Techniques like X-rays, ultrasonography, and computed tomography (CT) scans visualize and confirm the mass. CT scans are particularly effective, often revealing a characteristic mottled appearance with air bubbles. Endoscopy, using a flexible tube with a camera, allows direct visualization of the bezoar to determine its characteristics and composition.
Treatment approaches vary based on the bezoar’s type, size, location, and the patient’s condition. For some bezoars, especially phytobezoars, initial treatment may involve conservative measures like dietary changes or the administration of enzymatic solutions (e.g., cellulase) or carbonated beverages (e.g., Coca-Cola) to help dissolve or soften the mass. These agents can break down the bezoar into smaller pieces for passage or easier removal.
If chemical dissolution is ineffective or the bezoar causes significant symptoms, endoscopic removal is often attempted. During endoscopy, specialized tools like snares, forceps, or jet sprays fragment the bezoar into smaller pieces for extraction or passage. For larger or stubborn bezoars, or in cases of complications like obstruction or perforation, surgical intervention may be necessary. Procedures range from open laparotomy to less invasive laparoscopic approaches, depending on the bezoar’s characteristics and location. Following removal, addressing underlying risk factors, such as dietary habits or medical conditions, is important to prevent recurrence.