Funding for this research was provided by:
Sub-program of the key project of Digestive Collaborative Development Center of Gastroenterology, Beijing Hospital Administration Center (xxz0607)
Received: 21 August 2020
Accepted: 19 January 2021
First Online: 30 January 2021
Ethics approval and consent to participate
: I confirm that I have read the Editorial Policy pages. This study was conducted with approval from the Ethics Committee of Beijing Chaoyang Hospital. This study was conducted in accordance with the declaration of Helsinki. Written informed consent was obtained from all participants.
: All patient guardians signed a document of informed consent.
: The authors declare that they have no competing interests.