CONTEXT: Pain, abdominal distention, and anxiety are major risk factors encountered after colonoscopy. Complementary and alternative treatments, such as abdominal massage and position change, are used to reduce the associated risk factors. OBJECTIVE: To determine the effect of position change and abdominal massage on anxiety, pain, and distension after colonoscopy. DESIGN: A randomized three-group experimental trial. SETTING AND PARTICIPANTS: This study was conducted with 123 patients who underwent colonoscopy at the endoscopy unit of a hospital located in western Turkey. METHODS: Three groups were formed: two interventional (abdominal massage and position change) and one control, each including 41 patients. Data were gathered using a personal information form, pre- and post-colonoscopy measurement form, the Visual Analog Scale (VAS), and the Spielberger State-Trait Anxiety Inventory. Pain and comfort levels, abdominal circumference values, and vital signs of the patients were measured at four evaluation times. RESULTS: In the abdominal massage group, the VAS pain scores and abdominal circumference measurements decreased the most and the VAS comfort scores increased the most 15 min after the patients were taken to the recovery room (p<0.05). Furthermore, bowel sounds were heard, and bloating was relieved in all patients in both intervention groups 15 min after they were taken to the recovery room. CONCLUSIONS: Abdominal massage and position change can be considered effective interventions for relieving bloating and facilitating flatulence after colonoscopy. Moreover, abdominal massage can be a powerful method for reducing pain and abdominal circumference and increasing patient comfort.