Introduction <p>More than half of the patients undergoing colonoscopy have moderate or higher anxiety, which can lead to adverse outcomes such as increased abdominal pain and bloating, increased pain sensitivity, and failed colonoscopies, requiring some psychological interventions to alleviate this anxiety.</p> Methods/design <p>Participants in the study will be selected from adults undergoing their first colonoscopy. After obtaining informed consent from the patient, a baseline survey assessment will be completed for the participants. Participants will be randomly assigned to the intervention group (consisting of a brief individualized psychological intervention the day before the examination) and to the usual care group (no psychological intervention). In order to understand participants’ baseline levels and the effectiveness of the intervention, measures of anxiety, heart rate, and blood pressure will be taken before the intervention (T1), at the end of the intervention (T2), and half an hour before the checkup on the next day (T3), and participants’ satisfaction and treatment adherence will be assessed after the checkup (T4).</p> Discussion <p>In daily clinical practice, there is increasing concern about the effects of adverse emotions such as anxiety on patients. This study will be guided by the emotional ABC theory and is expected to bring targeted and more profound health education guidance to patients. The results of this study will help to explore the effectiveness of this intervention program and provide a theoretical basis for clinical practice.</p> Trial registration <p>The China Clinical Trials Center: ChiCTR2300073765; Data registered: 20/7/2023.</p>