['chronic constipation']
['asp0456', 'placebo']

        Inclusion Criteria:

          -  Patient who had SBM* (Spontaneous bowel movement) less than 3 times per week, more
             than six months prior to the provisional registration

               -  *Defecation without procedure of laxative, suppository, enema, or stool
                  extraction on the day or preceding day of the defecation

          -  Patient who was affected with one or more following symptoms before more than six
             months of provisional registration:

               -  Straining during at least 25% of defecations

               -  Lumpy or hard stools in at least 25% of defecations

               -  Sensation of incomplete evacuation for at least 25% of defecations

          -  Loose stools are rarely present without the use of laxatives more than six months
             prior to the provisional registration.

          -  Patients who had pancolonoscopy or contrast enema (or sigmoidoscopy) after the onset
             of chronic constipation symptom and had no organic changes

        Exclusion Criteria:

          -  Patient who has met IBS-C diagnostic criteria from Rome III more than six months prior
             to provisional registration. Meaning that patient who had recurrent abdominal pain or
             discomfort at least 3 days/month in last 3 months associated with two or more of the
             following, and patient who was affected with following IBS symptoms more than six
             months prior to the provisional registration:

               -  Improvement with defecation

               -  Onset associated with a change in frequency of stool

               -  Onset associated with a change in form (appearance) of stool

          -  Patient with history of surgical resection of stomach, gallbladder, small intestine,
             or large intestine (excluding resection of appendicitis and benign polyp)

          -  Patient with history or current evidence of inflammatory bowel disease (Crohn's
             disease or ulcerative colitis)

          -  Patient with history or current evidence of ischemic colitis

          -  Patient currently affected by infectious enteritis

          -  Patient currently affected by hyperthyroidism or hypothyroidism

          -  Patient with apparent mechanical obstruction (i.e. patient with ileus caused by
             hernia)

          -  Patient with mega colon or mega rectum

          -  Patient currently affected by constipation due to anorectal dysfunction

          -  Patient currently affected by drug induced constipation.

          -  Patient with constipation due to other organic disease

          -  Patient currently affected by active peptic ulcer

          -  In the case of a female, the one currently affected by endometriosis or uterine
             adenomyosis

          -  Patient with high depression or anxiety considered to influence drug evaluation

          -  Patient with history of abuse of drug or alcohol within a year before consent
             acquisition, or with current abuse

          -  Patient who used or underwent or will use or undergo drug/therapy/test prohibited to
             combine 3 days before the start of bowel habit observation period (Day -17) or
             thereafter (however, patient who used or underwent restricted drug/therapy according
             to Protocol may be enrolled provisionally)

          -  Patient with history or current evidence of malignant tumor

          -  Patient currently affected by serious cardiovascular disease, respiratory disease,
             kidney disease, hepatic disease, gastrointestinal disease (excluding CC), hemorrhagic
             disease, or neural/mental disease

          -  Patient with history of drug allergy
      