IBC Oxford University Poster Abstract 20 - Early small bowel obstruction by phytobezoar related to zopiclone induced amnesia after revisional Roux-en-Y gastric bypass: a case report
Authors: Salgado Macías N , Patiño Araujo B , Salgado Báez M E , Villavicencio Logroño G P 
Published: February 2025

Abstract

Introduction
Bowel obstruction following Roux-en-Y gastric bypass (RYGB) is observed in 1.5% to 11% of patients, with small bowel obstruction (SBO) compromising only 1.8% of these cases. SBO is categorized by time of onset as either early, within 30 days post-surgery, or late. Early obstruction typically involves surgical technical errors or dietary noncompliance. Phytobezoars, such as the one observed in our case, account for less than 1% of SBOs post-RYGB. Zopiclone, a nonbenzodiazepine hypnotic, has a maximum recommended dosage of 7.5 mg daily. Anterograde amnesia is a rare side effect of zopiclone, particularly at higher doses. Although the patient did not initially report zopiclone use, a psychiatric evaluation following the complication revealed frequent self-medication with this hypnotic. This case report is unique because phytobezoar-induced SBOs are rare and generally manifest months or years after the initial surgery. However, in our case, the obstruction occurred within the first 48 postoperative hours, in a technically correct surgery, and under unexpected circumstances.

Case Presentation
A laparoscopic revisional Roux-en-Y gastric bypass was successfully performed on a 59-year-old woman. The patient was discharged 24 hours after the procedure with detailed medical and nutritional instructions. However, she was readmitted 24 hours later due to acute epigastric pain and multiple episodes of vomiting. She denied any dietary indiscretions or taking non-prescribed medications. On physical examination, the patient had abdominal distension and epigastric tenderness, without signs of peritonitis. Blood analysis revealed leukocytosis with neutrophilia. A contrast CT scan showed dilated small bowel loops, right pleural effusion, and some free gas in the mediastinum. An emergency diagnostic laparoscopy revealed a normal gastric pouch and preserved anastomoses, along with dilated small bowel loops. The jejunojejunal anastomosis was disassembled, revealing undigested solid food content, including seeds, causing intestinal obstruction. The organic material was removed, and the anastomosis was reconstructed. Additionally, mesenteric gaps were closed, abdominal lavage was performed, and a left subphrenic drain was inserted. Postoperatively, the patient developed oliguria and was diagnosed with abdominal sepsis and Acute Kidney Injury (AKIN) II by the critical care team. Antibiotic and diuretic therapies were adjusted, and parenteral nutrition was started. A psychiatric consultation revealed the patient had been self-medicating with zopiclone at four times the recommended dose (30 mg each night). This had caused an anterograde amnesic episode due to the overmedication, resulting in her inability to remember her alimentary transgression. The patient was hospitalized for 10 days, during which she overcame her sepsis and achieved oral tolerance. Psychiatric, medical, and nutritional follow-up were arranged for her thereafter.

Conclusion
This case underscores the critical importance of obtaining a comprehensive medical history during initial patient evaluation. Patients must be informed of the necessity of disclosing all medications, including over the counter and self-prescribed drugs. In this instance, zopiclone-induced anterograde amnesia was identified as the precipitating factor for intestinal obstruction. Early identification of medication misuse is essential to prevent such complications and to ensure optimal patient outcomes.