['irritable bowel syndrome with constipation (ibs-c)']
['linaclotide', 'placebo']

        Inclusion Criteria:

          -  Patients who had abdominal pain or discomfort repeatedly for at least 3 days per month
             during the 3 months before screening examination associated with at least 2 out of the
             following 3 conditions: (1) Improvement with defecation; (2) Onset associated with a
             change in frequency of stool; and (3) Onset associated with a change in form
             (appearance) of stool, and had the above symptom (IBS symptom) 6 months or more before
             the screening examination period

          -  Patients with ≥ 25% of stools hard or lumpy (with each bowel movement occurring
             without antidiarrheal, laxative, suppository or enema) and <25% of them loose (mushy)
             or watery during the 3 months before the screening examination

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

        Exclusion Criteria:

          -  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 affection of inflammatory bowel disease (Crohn's
             disease or ulcerative colitis)

          -  Patient with history or current affection of ischemic colitis

          -  Patient currently affected by infectious enteritis

          -  Patient currently affected by hyperthyroidism or hypothyroidism

          -  Patient currently affected by active peptic ulcer

          -  In the case of a female patient, 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

          -  Patient with history or current affection of malignant tumor

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

          -  Patient with history of drug allergy
      