Inclusion Criteria:  At the time of provisional registration  Patients diagnosed with chronic constipation using the Rome IV criteria for the diagnosis of chronic constipation Age: 20 years or older (at the time of obtaining consent) Gender: Any outpatients Patients for whom written consent can be obtained Patients who can record defecation, etc. in the patient diary  At the time of registration: Dosing start criteria Patients with the following ・'Loss of defecation desire'* in the second week of the observation period (1 week before the start of the treatment period)  *"Loss of defecation desire " refers to patients whose "presence or absence of defecation desire" on the patient questionnaire was "4. almost never" or "5. never".  Exclusion Criteria:  At the time of temporary registration Exclude patients with any of the following conditions  Patients with organ-related constipation or suspected of having organ-related constipation Patients with or suspected of having functional ileus Patients with or suspected of having inguinal hernia Patients with a history of open abdominal surgery within 12 weeks prior to obtaining consent (excluding appendicitis resection) Patients with a history of surgical or endoscopic procedures related to gallbladder resection and papillotomy Patients with complications of malignancy However, patients who have undergone radical surgery or who have completed chemotherapy or radiotherapy may be registered. Pregnant women, lactating women, women who may be currently pregnant, or patients who cannot give consent to use contraception while participating in the study Patients with serious renal, hepatic, or cardiac disease Patients with drug allergy to the study drug Patients who are participating in other clinical studies, or who have participated in other clinical studies within 4 weeks prior to obtaining consent However, observational studies are excluded. Other patients who are judged by the principal investigator or sub-investigator to be inappropriate for this study.  At the time of registration: Dosing start criteria  Patients who increased the dose of concomitantly restricted drugs during the observation period Patients who used concomitantly prohibited drugs during the observation period