['chronic idiopathic constipation']
['plecanatide', 'placebo']

        Inclusion Criteria:

          -  Male or female aged 18-80, inclusive

          -  Meets modified Rome III criteria for functional chronic idiopathic constipation for at
             least 3 months with symptom onset for at least 6 months

          -  Completed a colonoscopy in accordance with American Gastroenterological Association
             (AGA) colon cancer screening guidelines (5 years), with no clinically significant
             findings

          -  Willing to maintain a stable diet during the study

        Exclusion Criteria:

          -  Loose stool (mushy) or watery (Bristol score 6 or 7) stool in the absence of any
             laxative or prohibited medicine for > 25% of Bowel Movements (BMs) during the 3 months
             prior to screening visit OR during the 14 day pre-treatment assessment

          -  Active peptic ulcer disease, diabetes or hypertension not adequately treated or not
             stable

          -  History of cathartic colon, laxative, enema abuse, or ischemic colitis

          -  Fecal impaction within 3 months of screening

          -  Patient has had /has any: diseases or conditions associated with constipation (GI or
             CNS), structural abnormality of the GI tract or gastric bypass surgery, pelvic floor
             dysfunction, pseudo-obstruction, active infectious gastritis, diverticulitis, anal
             fissures or any disease or condition that can affect GI motility or defecation or can
             be associated with abdominal pain

          -  Unexplained and clinically significant "alarm symptoms" including lower GI bleeding,
             iron-deficiency anemia, weight loss or systemic signs of infection or colitis

          -  Major surgery, stroke or myocardial infarction (MI) within 60 days of screening

          -  Participated in a previous plecanatide clinical trial
      