Purpose: To examine registered nurses’ gastrointestinal health and their use of complementary, alternative, and integrative medicine (CAIM) for constipation, and to explore demographic and professional correlates of CAIM adoption. Methods: A cross-sectional survey was conducted using an online questionnaire to assess demographics, professional background, gastrointestinal health, and CAIM use. Items also captured knowledge sources, perceived barriers, and facilitators related to the use of CAIM. Results: Constipation was reported by approximately one-quarter of the nurses. About 70% of nurses used CAIM for constipation. The most frequently used modalities were probiotics, dietary fiber, lifestyle modification, and abdominal massage. Nurses primarily acquired knowledge from informal sources rather than evidence-based literature. The primary barrier to CAIM use was limited familiarity, and the main facilitator was fewer side effects. CAIM use was more likely among nurses who met recommended physical activity thresholds. It was not significantly associated with other demographic or professional characteristics. Conclusion: Nurses use CAIM for bowel health, yet reliance on informal sources reveals an evidence–literacy gap. Education, better access to high-quality syntheses, and organizational support may advance evidence-informed integration. Future work should expand modality coverage, include psychosocial and occupational measures, and use longitudinal or model-based designs to clarify mechanisms and causality.