This retrospective observational study aims to evaluate the relationship between preoperative fasting duration and gastric residue in pediatric patients undergoing upper gastrointestinal endoscopy for gastrointestinal symptoms or pathology. The study will assess the associations between gastric residue, gastrointestinal symptoms, underlying gastrointestinal diseases, and endoscopic findings. Data will be retrospectively collected from hospital records, anesthesia records, and endoscopy reports to investigate whether prolonged fasting duration reliably predicts an empty stomach in pediatric gastrointestinal patients.

Pulmonary aspiration is one of the most feared complications in pediatric anesthesia, and preoperative fasting is routinely used to reduce gastric content and aspiration risk. Current pediatric fasting guidelines support more liberal fasting regimens, especially for clear liquids, in order to avoid unnecessary prolonged fasting. However, prolonged fasting duration does not always guarantee an empty stomach, particularly in pediatric patients with gastrointestinal symptoms or underlying gastrointestinal pathology.

Recent studies evaluating gastric contents in children have mainly focused on gastric ultrasonography and estimated gastric volume in healthy pediatric populations. Data regarding directly observed gastric residue during upper gastrointestinal endoscopy in pediatric gastrointestinal patients remain limited.

This retrospective observational single-center study will include pediatric patients who underwent upper gastrointestinal endoscopy for gastrointestinal symptoms or pathology between January 2025 and April 2026. Data will be retrospectively obtained from hospital information systems, anesthesia records, electronic medical records, and endoscopy reports.

Demographic characteristics, gastrointestinal symptoms, underlying gastrointestinal diseases, medication use, endoscopic findings, preoperative fasting duration, and endoscopically observed gastric residue will be evaluated. Gastric residue severity will be categorized as none, mild, moderate, or severe. In addition, clinically relevant residue will be defined as moderate or severe gastric residue.

The primary objective of the study is to evaluate the relationship between preoperative fasting duration and gastric residue severity. Secondary analyses will assess factors associated with clinically relevant gastric residue, including gastrointestinal inflammatory disease and other clinical variables.

The findings of this study may contribute to a better understanding of gastric residue patterns in pediatric gastrointestinal patients and support more individualized perioperative fasting assessment approaches.

Inclusion Criteria:

• Pediatric patients aged under 18 years
• Patients who underwent upper gastrointestinal endoscopy for gastrointestinal symptoms or pathology
• Patients with available hospital records, anesthesia records, and endoscopy reports
• Patients with documented preoperative fasting duration
• Patients with documented endoscopic assessment of gastric residue

Exclusion Criteria:

• Patients aged 18 years or older
• Patients with missing or incomplete data for key study variables
• Patients without documented preoperative fasting duration
• Patients without documented gastric residue assessment during endoscopy
• Duplicate endoscopy records from the same patient, if only the first eligible procedure is included

Pediatric patients undergoing upper gastrointestinal endoscopy for evaluation of gastrointestinal symptoms or suspected gastrointestinal pathology at a single tertiary care center will be included in this retrospective observational study. The study population will consist of patients evaluated between January 2025 and April 2026. Data will be retrospectively obtained from hospital information systems, anesthesia records, electronic medical records, and endoscopy reports. The study will evaluate demographic characteristics, gastrointestinal symptoms, preoperative fasting duration, endoscopic findings, underlying gastrointestinal diseases, medication use, and endoscopically observed gastric residue.

Individual participant data will not be publicly shared because the study involves retrospective review of pediatric patient records and contains potentially sensitive clinical information.