Objective To understand the main causes of social alienation in patients with colorectal cancer undergoing enterostomy, and to provide a reference to help patients better return to and adapt to society. Methods Semi-structured in-depth interviews of 19 colorectal cancer patients undergoing enterostomy were conducted in pursuant to descriptive phenomenological design. Qualitative content analysis was performed to summarize and extract themes from the interview texts. Results A total of 3 themes and 8 subthemes were extracted:impaired social skills (symptom distress, high care needs, limited daily life); insufficient social motivation (strong sense of stigma, emergence of sense of meaninglessness, heightened insecurity); and inadequate social support system (poor family function, cognitive bias from the public). Conclusion Patients with colorectal cancer undergoing enterostomy may experience social alienation due to impaired social skills, insufficient motivation, and lack of support. Medical staff should strengthen self-management education and support for this population, pay attention to psychological counseling, and strengthen family and social support to help them recover and return to society.