The goal of this observational study is to evaluate the diagnostic value and safety of capsule endoscopy in patients with gastrointestinal bleeding. The main questions it aims to answer are:

What is the overall detection rate of bleeding lesions using capsule endoscopy? What is the completion rate of capsule endoscopy, and how long does it take for the capsule to pass through the stomach and small intestine? What adverse events (such as capsule retention) occur during or after the procedure?

Participants who underwent capsule endoscopy for gastrointestinal bleeding at Changhai Hospital between January 2021 and December 2025 will:

Have their existing medical records (including endoscopy reports, procedure notes, and follow-up records) reviewed by researchers Have their personal information anonymized and protected Not be required to undergo any additional tests, procedures, or visits This is a retrospective study that only analyzes previously collected data. No new interventions or patient contact is involved.

Inclusion Criteria:

• Age ≥18 years old;
• Obvious symptoms of gastrointestinal bleeding (such as hematemesis, melena, hematochezia, and positive fecal occult blood test);
• From January 2021 to December 2025, magnetic capsule endoscopy was performed at Chang Hai Hospital

Exclusion Criteria:

• Known or suspected intestinal obstruction, stenosis, or fistula;
• Severe asthma, swallowing disorders, or gastroparesis and other motility disorders;
• History of abdominal surgery that has affected the normal structure of the digestive tract in the past;
• When capsule retention occurs, the problem cannot be solved through surgical means due to subjective or objective reasons;
• Implantable medical devices such as pacemakers, cochlear implants, drug infusion pumps, and nerve stimulators are installed inside the body, except for MRI compatible products;
• Pregnant women;
• Patients who need to undergo MRI examination before capsule endoscopy is discharged;
• Suffering from severe heart and lung diseases (severe myocardial infarction, arrhythmia, heart failure, respiratory failure, etc.);
• Refusing capsule endoscopy or gastroscopy examination;
• Researchers believe that there are any other influencing factors that are not suitable for participants to participate in the study

Participants who underwent magnetically controlled capsule endoscopy for gastrointestinal bleeding at Changhai Hospital between January 2021 and December 2025