With recent significant improvements in artificial intelligence (AI), especially in the field of deep learning, an increasing number of studies have evaluated the use of AI in endoscopy to detect and diagnose gastrointestinal (GI) lesions. The present review summarizes current publications on the use of AI in GI endoscopy and focuses on the challenges and future of AI-aided systems. We expect AI to provide an effective and practical method for endoscopists in lesion detection and characterization as well as in quality control in endoscopy. However, so far, most studies have remained at the preclinical stage. More attention should be paid in the future to the use of AI in reallife clinical applications.Artificial intelligence (AI), first proposed in the 1950s, 1 uses computers to simulate certain thought processes and forms of intelligent behavior. In recent years, one way to achieve AI, namely machine learning, has been used in a variety of medical fields, such as radiology, pathology, ophthalmology, orthopedics, obstetrics, and gynecology, in an attempt to improve physicians' diagnoses. 2 In the field of gastrointestinal (GI) endoscopy endoscopists face heavy workloads, and different kinds of endoscopic images, such as those of esophagogastroduodenoscopy, colonoscopy and capsule endoscopy, has led specialty gastroenterology societies to call for practical and effective methods in order to improve the efficiency and quality of endoscopy in daily clinical practice.With the advent of data-driven deep learning (DL), the inefficient and incomplete feature extraction that results from manual extraction by using traditional machine learning has been thoroughly addressed, and this has revolutionized the research and development of AI. 3,4 After having been trained by a large number of labeled images, the DL algorithm can classify enormous quantities of images. 3 A variety of DL algorithms have thus been created, of which convolutional neural networks (CNN) are the most widely used for medical image recognition.However, DL has some defects, including the requirement of highquality databases and its black-box nature, which have been summarized in Table 1. AI technology used in GI endoscopy falls mainly in two groups:computer-aided detection (CADe) system and computer-aided diagnosis (CADx) system. 5 CADe system is designed to detect and track GI lesions, while CADx system focuses mainly on identifying and characterizing them. Moreover, computer-aided monitoring (CADm) systems are designed for evaluating the examination procedure and † These authors contributed equally to this article.