Endoscopic Treatment of a Giant Gastric Bezoar: Sequential Use of Alligator Forceps and Snare Fragmentation

Abstract

We report the case of a 79-year-old man with a giant gastric diospyrobezoar (50 × 30 mm) who presented with epigastric pain. Two weeks of cola dissolution therapy at home was ineffective. During endoscopy, alligator forceps were used to create grooves on the hard, smooth surface of the bezoar, enabling a 30-mm polypectomy snare to fragment the bezoar into pieces smaller than 1 cm. Residual fragments passed spontaneously, and complete resolution was confirmed by follow-up endoscopy three weeks later. The patient was discharged on postprocedure day 3 without complications. This case demonstrates that the sequential use of alligator forceps and a polypectomy snare can be an effective endoscopic technique for giant gastric bezoars with hard, smooth surfaces, potentially avoiding surgical intervention even in high-risk elderly patients.

Introduction

A gastric bezoar is a condition in which food and foreign materials combine to form an insoluble stones in the stomach. Based on their composition, gastric bezoars can be categorized into plant bezoars (phytobezoars), hair bezoars (trichobezoars), pharmacobezoars (medications), and lactobezoars (milk products) [1]. In Japan, plant bezoars, particularly those formed from persimmons (diospyrobezoars), are the most common subtype, owing to the high tannin content of persimmon skin, which polymerizes upon contact with gastric acid to form a hard, insoluble stones [1, 2]. Several factors predispose patients to bezoar formation, including prior gastric surgery, diabetes mellitus with gastroparesis, hypothyroidism, impaired mastication, and excessive ingestion of high-fiber foods [2]. The incidence of gastric bezoars among patients undergoing upper gastrointestinal endoscopy has been estimated at approximately 0.31%, although reported rates vary widely across studies [2].

Bezoars are primarily formed and found in the stomach but can migrate distally, causing intestinal obstruction, or can cause gastric outlet obstruction, which may require surgical intervention [3]. Treatment approaches range from chemical dissolution with carbonated beverages to endoscopic fragmentation and, when these measures fail, surgical removal [1]. Endoscopic treatment is generally preferred as a first-line intervention because of its minimally invasive nature; however, giant bezoars, typically defined as those exceeding 5 cm in diameter, pose a particular endoscopic challenge because of their size and surface hardness [4, 5]. Here, we report our experience in successfully treating a giant gastric diospyrobezoar endoscopically using a sequential technique involving groove creation with alligator forceps followed by polypectomy snare fragmentation, thereby avoiding the need for surgical intervention.

Case presentation

A 79-year-old Japanese man with a history of chemoradiation therapy for anal cancer presented with epigastric pain unrelated to meal timing. He was initially seen at a local clinic in April 2025 and referred for further evaluation. CT imaging of the abdomen demonstrated a well-defined hyperdense mass in the stomach measuring 50 mm in its long diameter and 30 mm in its short diameter, consistent with a giant gastric bezoar (Figure 1). Upper gastrointestinal endoscopy confirmed the presence of the bezoar, which had a black, smooth surface (Figure 2), along with an A2 gastric ulcer at the angulus, identified as the source of his epigastric pain.

Figure 1. CT images of the giant gastric bezoar.

(A) Axial CT image showing a hyperdense mass (arrow) within the gastric lumen, measuring 50 mm in its long diameter. (B) Coronal CT image showing the hyperdense bezoar (arrow) within the gastric lumen.

Figure 2. Upper gastrointestinal endoscopy at initial presentation.

(A) A giant bezoar with a black, smooth, and hard surface occupying the gastric lumen. (B) An A2 gastric ulcer at the angulus of the lesser curvature, identified as the source of the patient's epigastric pain.

The patient reported having a persimmon tree on his property and frequently consuming persimmons, strongly supporting a diagnosis of diospyrobezoar. Although the exact period of formation was unknown, a previous upper gastrointestinal endoscopy performed at another institution in December 2021 had revealed no bezoar, indicating that it had formed within approximately 3 years and 4 months.

Given the hard consistency of the bezoar, preprocedural cola dissolution therapy was initiated at home for two weeks (500 mL of regular cola per day, taken after meals); however, no appreciable reduction in bezoar size was observed.

The patient was admitted on day 1 in April 2025 for elective endoscopic treatment. Laboratory investigations at admission revealed a hemoglobin level of 11.2 g/dL, consistent with mild anemia likely attributable to chronic blood loss from the gastric ulcer. Under conscious sedation, upper gastrointestinal endoscopy was performed. The bezoar surface appeared black and smooth. Assessment with alligator forceps confirmed a firm consistency; however, the surface was amenable to mechanical grooving. Surface grooves were deliberately created using the alligator forceps to provide anchorage for the snare (Figures 3A-3B). A 30-mm-diameter polypectomy snare was then applied, and the bezoar was fragmented into pieces smaller than 1 cm (Figures 3C-3D). The entire procedure was completed in 27 minutes. Complete endoscopic retrieval was not performed; the residual fragments were expected to pass spontaneously through the GI tract.

Figure 3. Endoscopic procedure.

(A) Assessment of bezoar hardness using alligator forceps. (B) Creation of surface grooves on the bezoar using alligator forceps. (C) Sequential fragmentation of the bezoar using a polypectomy snare engaged in the surface grooves. (D) Post-fragmentation view showing multiple fragments smaller than 1 cm.

Second-look endoscopy on day 2 confirmed that only a few small fragments remained in the stomach, none of which were judged too large to pass through the pylorus (Figure 4A). The patient was commenced on vonoprazan 20 mg once daily for six weeks for treatment of the A2 gastric ulcer. A soft diet was maintained for the first two postprocedure days. The patient remained free of complications and was discharged home on day 4. Follow-up upper gastrointestinal endoscopy in May 2025 confirmed complete disappearance of the gastric bezoar (Figure 4B).

Figure 4. Follow-up endoscopy.

(A) Second-look endoscopy on day 2 showing a few small residual fragments, all judged small enough to pass spontaneously through the pylorus. (B) Follow-up endoscopy in May 2025 confirming complete disappearance of the gastric bezoar.

Discussion

Gastric bezoars are classified by composition into phytobezoars (plant material), trichobezoars (hair), pharmacobezoars (medication residues), and lactobezoars (milk products). Diospyrobezoars, formed from persimmon tannins that polymerize in the acidic gastric environment, are the most prevalent subtype in Japan [1, 6]. Common predisposing factors include prior gastric surgery, diabetic gastroparesis, hypothyroidism, and impaired gastric motility [2]. Gastric ulcers are a recognized complication of bezoars and are attributed to pressure necrosis of the gastric mucosa [2]; in our patient, an A2 ulcer at the angulus was identified as the source of epigastric pain and resolved following bezoar removal. Treatment follows a stepwise approach: chemical dissolution, endoscopic fragmentation, and surgical removal [1].

Chemical dissolution using cola beverages exploits their carbonic and phosphoric acid content to soften the bezoar matrix. Systematic reviews have reported complete dissolution rates of approximately 50% for phytobezoars treated with cola [7]. Pretreatment with cola may also facilitate subsequent endoscopic fragmentation even when complete dissolution is not achieved [6]. In the present case, two weeks of home cola therapy failed to produce a meaningful reduction in size, consistent with prior reports documenting limited efficacy for hard, well-formed diospyrobezoars [7]. The resistance to cola dissolution in our case likely reflects the advanced degree of tannin polymerization within the bezoar matrix.

Endoscopic fragmentation is the preferred definitive treatment for bezoars that fail chemical dissolution. Various instruments have been employed, including biopsy forceps, snares, basket retrievers, needle knives, and argon plasma coagulation [1, 6]. Giant bezoars, however, present a particular challenge: their large size and smooth surface may prevent effective snare engagement. In the present case, the smooth, hard surface initially prevented the polypectomy snare from grasping the bezoar.

We addressed this challenge by first using alligator forceps to mechanically create surface grooves, thereby providing anchorage for the snare. This sequential approach, alligator forceps groove creation followed by fragmentation with a 30-mm polypectomy snare, allowed effective reduction of the bezoar to pieces smaller than 1 cm without lithotripsy or other advanced equipment. Jinushi R et al. reported a similar sequential strategy in a patient with a 10-cm gastric bezoar, using electrohydraulic lithotripsy, alligator forceps, and snares [5]. In their case, lithotripsy was required to create an initial channel, whereas our case was managed with alligator forceps alone for surface preparation, suggesting that forceps-based groove creation may be sufficient for moderately sized, hard bezoars. Hu X et al. described a novel tangential sawing technique using seesaw-type guidewire movements in a retrospective series of 10 patients with giant bezoars, achieving complete fragmentation in all cases [8]. Huang Z et al. reported successful removal using a dual knife combined with an electric snare [4], and Peng J et al. developed a customized device comprising injection needle sheaths and a guidewire for flexible snare-size adjustment [9]. In contrast to these specialized approaches, our technique relies entirely on standard instruments that are widely available in endoscopy suites, which may enhance its practical reproducibility.

The decision not to perform complete endoscopic retrieval and instead allow the residual fragments to pass spontaneously was supported by second-look endoscopy on day 2, which confirmed that all remaining fragments were of a size compatible with passage through the pylorus. This strategy minimizes procedural time and reduces the risk of iatrogenic complications and has been described in prior reports as an acceptable approach when the fragments are confirmed to be small [5, 6].

Surgery was avoided in this elderly patient with a prior history of chemoradiation therapy for anal cancer, a population associated with elevated perioperative risk. Our case demonstrates that giant gastric bezoars can be effectively managed endoscopically, with a short hospital stay and complete resolution confirmed at short-term follow-up, even in high-risk patients.

Conclusions

We report a case of a giant gastric diospyrobezoar (50 × 30 mm) successfully treated by endoscopic fragmentation using sequential alligator forceps groove creation and polypectomy snare fragmentation, thereby avoiding surgical intervention. Preprocedural cola dissolution therapy was ineffective, underscoring the limitations of chemical treatment for hard diospyrobezoars. This case demonstrates that the sequential use of alligator forceps and a polypectomy snare may represent a feasible, minimally invasive option for selected patients with giant gastric bezoars with a hard, smooth surface when standard dissolution therapy has failed. As this is a single case report, these findings cannot be generalized; prospective studies with larger patient cohorts are needed to validate the efficacy and safety of this approach, particularly in elderly patients with significant comorbidities.