The purpose of the study is to determine the accuracy of detachable string magnetically controlled capsule endoscopy(DS-MCE) as a follow-up method for patients with previous esophageal diseases.

Esophagogastroduodenoscopy (EGD) is recognized as the gold standard for detection and follow-up of esophageal diseases,allowing for direct mucosal visualization and therapeutic intervention. EGD is however an invasive procedure and there is potential for procedure-related complications, such as perforation and bleeding.Esophageal capsule endoscopy(ECE)provides a novel noninvasive approach to visualize the esophagus.The main drawback for the use of ECE is its unreliable transit time which often renders an inadequate visualization of the esophagus.Thus investigators have developed the detachable string magnetically controlled capsule endoscopy(DS-MCE) which can control the movement of the capsule through the string.

The ds-MCE system consists of two parts: the magnetically controlled capsule endoscopy (MCE) system and a transparent latex sleeve with a hollow string. The magnetically controlled capsule endoscopy (MCE) system (Ankon Technologies, Shanghai, China) detects focal lesions in the stomach with comparable accuracy with conventional EGD. One end of the hollow string is a transparent thin latex sleeve that can be wrapped on the surface of the capsule, and the other end of the string is connected to the syringe. The capsule, which is partially enclosed within the sleeve, can be actively moved in the esophagus through the control of string. In this case, investigator can examine the entire esophageal mucosa several times under real time views. The capsule then could be detached from the string system through injecting air into the hollow string with the syringe after completing the examination of esophagus. The pilot study of ds-MCE confirmed it was a feasible, safe and well-tolerated method for completely viewing esophagus and stomach, without the need for sedation. Besides, the 8-10h battery life of the ds-MCE enables complete examination of the small bowel, which provides the possibility for screening pathological changes in the entire gastrointestinal tract.

This study is a prospective, multi-centered, diagnostic accuracy study. The primary outcome is the diagnostic accuracy of ds-MCE in identifying esophageal diseases. Second outcomes include the visualization and cleanliness of Z-line, safety and patient satisfaction of DS-MCE.

Inclusion Criteria:

1. Gender is not limited.
2. Patients aged between 18-75 years or older.
3. Both inpatients and outpatients.
4. Patients with previous esophageal diseases who are scheduled to undergo EGD for follow-up.
5. Able to provide informed consent.

Exclusion Criteria:

1. Patients aged less than 18 years.
2. Patients with active upper gastrointestinal bleeding.
3. Patients who have participated in or are participating in other clinical trials within three months.
4. Patients with cancer on active treatment with chemotherapy and/or radiation therapy.
5. Pregnancy or suspected pregnancy.
6. Suspected or known intestinal stenosis or other known risk factors for capsule retention.
7. Pacemaker or other implanted electromedical devices which could interfere with magnetic resonance.
8. Patients with dysphagia.

After finishing this study, we will make the data available to other researchers:

including study protocol, statistical analysis plan (SAP), informed consent form (ICF), clinical study report (CSR)

3 years.

The website of the journal where the results published, and ClinicalTrials.gov web site.