Background: Sleep disturbance is a common symptom in CC patients, and it is positively related to greater somatic and psychiatric symptoms. Methods: The participants were 126 adult outpatients with CC. The measures were: constipation-Constipation Scoring System (CSS) and Patient Assessment of Constipation-Symptoms (PAC-SYM); sleep-Pittsburgh Sleep Quality Index (PSQI); anxiety-General Anxiety Disorder-7 (GAD-7); depression-Patient Health Questionnaire-9 (PHQ-9); and QOL-Patient Assessment of Constipation Quality of Life (PAC-QOL) and SF-36. Patients were divided into sleep-disorder and normal-sleep groups by their PSQI scores. Results: The sleep-disorder group had significantly higher rates of incomplete defecation and blockage and higher CSS scores, PAC-SYM total scores, and PAC-SYM rectal-item scores than the normal-sleep group. GAD-7 and PHQ-9 scores were significantly higher in patients with poor sleep. Furthermore, sleep disorders, depression, and anxiety were all positively correlated with constipation severity. "Worry/anxiety" score of PAC-QOL scale was significantly higher and scores for seven SF-36 subscales were significantly lower in patients with poor sleep. In addition, correlation analyses showed significant negative relations between QOL and constipation, sleep disturbance, anxiety as well as depression. However, multiple regression revealed that PAC-QOL was positively associated with severe constipation and SF-36 was negatively associated with anxiety and depression. But sleep disturbance was not the independent risk factor for QOL of CC patients. Conclusion: Sleep disorders may worsen the physical-and mental health of CC patients. Sleep disturbance may lower CC patients' QOL indirectly through the combined effects of anxiety, depression, and constipation.