Background: Constipation is a common complication among patients undergoing open-heart surgery, often prolonging hospital stays and contributing to significant morbidity, with rare cases leading to mortality. The Murdoch Bowel Protocol provides a straightforward and validated approach for managing constipation. Aim of the study: To evaluate the effect of implementing the Murdoch Bowel Protocol on constipation among open-heart surgery patients. Research design: A quasi-experimental research design was utilized. Subjects: A purposive sample including (90) adult post-open-heart surgery patients classified into two equal groups of 45 each (study and control group). Setting: Conducted at Cardiothoracic Surgery Hospital of Minia University in Minia governorate. Tools: Three tools were utilized to collect data, the first tool is a structured interview assessment sheet for demographic and medical data, and the second tool includes a bowel assessment sheet divided into 2 parts: part I: Constipation Assessment Scale, part II: Bristol Stool Form Scale, the third tool include: Intake and Output chart. Results: The study group demonstrated a statistically significant difference in preventing constipation occurrence compared to the control group on the tenth day. Conclusion: The study findings indicate that patients who received the Murdoch bowel protocol have a lower incidence rate of constipation than those patients who didn't receive the Murdoch bowel protocol. Recommendation: Application of Murdoch bowel protocol to reduce the occurrence of constipation among critically ill patients in the intensive care unit.