The trial is a prospective,multi-center, randomized and self-controlled clinical trial. The research plan will be implemented in a clinical trial center with the qualification of clinical trial agency, and 128 subjects will be planned to be included. Subjects signing the Informed Consent Form, meeting the trial conditions and all inclusion criteria and failing to meet any exclusion criteria will be included in the research. The trial device was Colon Capsule Endoscope System for colonoscopy(PC-I) manufactured by ANKON Technologies Co.,Ltd. while the comparator device was Capsule Endoscopy System(PillCam COLON2) manufactured by Given Imaging Inc. The main evaluation indicator is the excellent rate of image quality, while secondary evaluation indicators are the consistency rate of lesion detection, completion rate of colonoscopy, discharge time of capsule endoscopy, colon passing time and device performance evaluation. Safety evaluation indicators include adverse events(or Serious adverse events), device-related adverse events(or Serious adverse events) and device defects. In the end, the effectiveness and safety of Colon Capsule Endoscopy diagnostic system manufactured by ANKON Technologies Co.,Ltd. for capturing and viewing colon images clinically were verified according to the above indicator results.

According to the relevant requirements of Standard for Quality Management of Medical Device Clinical Trials (Order No. 25 of the National Health and Family Planning Commission of the People's Republic of China of China Food and Drug Administration), the sample size was estimated based on the excellent rate of the image quality of the main endpoint by referring to the domestic and foreign literatures using positive comparator devices. Combined with literatures and comments of clinical experts, the research set the excellent rate of image quality of comparator device Ps as 95%, and estimated the excellent rate of image quality of trial device Pt as 95%. In the research, the non-inferiority trial design was adopted, with α = 0.025 (unilateral), assurance 1 - β = 0.8, and non-inferiority boundary value of -10%, and self-control was adopted. It is assumed that the redundant parameter (that is, the proportion of subjects whose evaluation results of image quality between trial devices and comparator devices are inconsistent) was 0.095 (that is, Pt (1 - Ps) + Ps (1 - Pt)), the total sample size of the two groups was 102 cases calculated by PASS2021, with 51 cases in each swallowing orders I and II. Considering the shedding and rejection rate of 20% during the trial, a total of 128 subjects were needed, with 64 cases in each swallowing orders I and II.

Inclusion Criteria:

• Age ≥ 18 years old (including 18 years old), male or female;
• Subjects intending to take capsule endoscopy and/or the electronic endoscopy of the lower digestive tract;
• The subject signed the ICF voluntarily.

Exclusion Criteria:

• Subjects suffering from swallowing obstruction or deglutition disorders;
• Subjects who underwent gastrointestinal abdominal surgery in the past 6 month (except for simple surgery unlikely to cause intestinal obstruction according to the clinical judgment of researchers).
• Subjects of CRC (advanced adenomatous polyp and CRC) failing to undergo the surgery;
• Subjects suffering from gastrointestinal obstruction, stenosis or fistula;
• Subjects being unable to take capsule endoscopy due to intestinal preparation failure;
• Subjects with cardiac pacemakers or other implantable electronic medical devices;
• Subjects failing to meet requirements for the abdominal surgery or refusing to take any abdominal surgery;
• Female subjects during pregnancy, lactation or having a pregnancy plan recent 3 months;
• Subjects who underwent colonoscopy within 2 years, with the negative result;
• Subjects suffering from type 1 or type 2 diabetes;
• Subject taking incomplete colonoscopy due to enteropathy of severe ulcerative colitis, radiation enteritis or non-steroidal anti-inflammatory drugs[4];
• Subjects suffering from any disease considered to increase the retention risk of the capsule endoscopy;
• Subjects currently participating in another clinical trial of drugs or devices;
• Other circumstances unsuitable for inclusion upon judgment by the researcher.