Effect of Box Breathing Exercise on Anxiety, Pain, and Pulmonary Function Tests in Patients Undergoing Colonoscopy

This study is a prospective, randomized controlled clinical trial designed to determine the effect of box breathing exercises on anxiety, pain, and pulmonary function in patients undergoing colonoscopy. Data will be collected using the Participant Characteristics Form, State Anxiety Inventory (SAI), Visual Analog Scale (VAS), and Pulmonary Function Test Monitoring Form. Patients scheduled for colonoscopy who meet the inclusion criteria will be informed about the study, and written informed consent will be obtained. Upon arrival at the endoscopy unit, all participants will complete the Participant Characteristics Form and the State Anxiety Inventory (SAI) under the supervision of researcher MA. Baseline pulmonary function tests will be performed using the Contec SP-10 Spirometer (China). After confirming eligibility and obtaining written informed consent, researcher GB will notify researcher YG, who will determine the participant's group allocation and communicate it to GB according to the randomization sequence. Before the procedure, 34 patients allocated to the intervention group will receive the box breathing intervention, whereas 34 patients in the control group will receive routine pre-procedural care. Patients in the intervention group will receive instruction from researcher GB on the box breathing technique (4-4-4-4 breathing) upon arrival at the endoscopy unit. The exercise consists of inhaling through the nose for 4 seconds, holding the breath for 4 seconds, exhaling slowly through the mouth for 4 seconds, and holding the breath again for 4 seconds, constituting one complete cycle. Participants will be instructed to continue practicing this breathing exercise until they are transferred to the procedure room. Participants in the control group will receive the unit's standard pre-procedural care. As part of routine practice, vital signs are assessed before the procedure. To maintain patient privacy, participants remove their clothing and wear a surgical gown. After being positioned in the left lateral position, petroleum jelly is applied to the anal region, and the colonoscopy is performed using a flexible colonoscope. All colonoscopy procedures will be performed by the same gastroenterology specialist to ensure procedural consistency. Immediately after the procedure, the State Anxiety Inventory (SAI), Visual Analog Scale (VAS), and Pulmonary Function Test Monitoring Form will be administered by researcher MA.

Inclusion Criteria: * are 18 years of age or older; * are scheduled to undergo colonoscopy; * are conscious, oriented, and able to cooperate; * provide written informed consent to participate in the study; * are able to speak and understand Turkish; and * have no physical disabilities that would interfere with study participation. Exclusion Criteria: * decline to participate or choose to withdraw from the study; * have a chronic respiratory disease; * have chest pain; * have nasal abnormalities (e.g., nasal septal deviation) or adenoid hypertrophy -that may affect ventilation; * have previously practiced box breathing exercises; or * have chronic pain.