The teaching method of BOPPPS combined with Case-Based Learning is different from the traditional "cramming duck" teaching method. It is oriented towards solving practical problems and encourages students to collect targeted information according to clinical problems [9]. Internet, libraries, and other resources are searched to inquire about relevant cases and materials. The experience of oneself and teachers are summarized to make a final diagnosis and formulate the best treatment plan. Through such a learning process, the eight-year medical program students are stimulated to have a strong interest in clinical medicine and a strong thirst for knowledge, which mobilize the enthusiasm, initiative, and creativity of the eight-year medical program students.
The BOPPPS teaching mode has been applied in many clinical teachings and has achieved good results. Students preferred the BOPPPS model more than the traditional instructional approach in student-teacher interaction, course satisfaction, analytical ability, learning initiative, clinical thinking ability, and self-study ability [9]. Liu et al. found that BOPPPS was likely a more effective and useful teaching model for promoting effectiveness of Physiology teaching. This is attributable to the flexibility and reproducibility as well as the increased learning initiatives [11]. The BOPPPS mode provides teachers with specific teaching methods and steps, which can make clinical teaching rounds more standardized and promote the improvement of teaching efficiency and teaching quality [12]. In addition, the introduction of BOPPPS model clinical teaching rounds displays theoretical knowledge in various backgrounds, which can attract the attention of interns and attach importance to teaching rounds [13].
The Case-Based Learning is designed according to the principle of the problem-based learning method. The case is the guide, and the questions run through the teaching process. Teaching plays a leading role in the process, and students are the main body of the teaching process, which can fully mobilize the interaction and interaction effect between teachers and students [14]. In the case introduction teaching process, the Case-Based Learning not only has the relevant advantages of problem-based teaching but also incorporates the characteristics of medical teaching, which can better improve students' enthusiasm and initiative in learning general knowledge. To develop students' clinical skills well. In the teaching process of Case-Based Learning, the teacher makes an appropriate teaching design according to the characteristics of the teaching content. On the basis of a good teaching design, the case is comprehensively and correctly explained, and the students are organized to discuss the case in groups [15]. During the discussion, students are encouraged repeatedly to think about the teaching content, thus providing students with self-creativity, helping to inspire students' divergent thinking, and improving students' learning initiative [16]. The case-introduction teaching method can transform the traditional teaching method into a scientific and modern teaching mode, with the teacher as the active student as the main body. It is conducive to cultivating students' ability to think independently and solve problems.
In recent years, the teaching mode combining BOPPPS and Case-Based Learning has been initially applied in practice. Chen et al. applied BOPPPS and Case-Based Learning in ophthalmology teaching were compared among students in a five-year programme, through which students develop their problem-solving skills, analytical skills and motivation for learning better than the traditional lecture-based learning [17]. Meanwhile, the BOPPPS and Case-Based Learning group has higher final examination scores and overall course satisfaction [17]. This joint teaching model takes students as the main body and emphasizes the importance of group cooperative learning and feedback information. The teaching mode can not only give full play to the advantages of the BOPPPS teaching model, which emphasizes the importance of teacher-student interaction but also makes up for it. The BOPPPS teaching model eliminates the shortcomings of the case teaching method with teachers as the main body and organically combines the content of textbooks with clinical cases, which will help students understand the clinical practice and mobilize their self-learning ability. It can be seen that the teaching method of BOPPPS combined with Case-Based Learning is worth promoting. This combination mode is applied to the practice of gastroenterology, which cultivates students' learning interests and innovation ability.