['irritable bowel syndrome with constipation (ibs-c)']
['syn-010 21 mg', 'syn-010 42 mg', 'placebo']

        Inclusion Criteria:

          -  Subjects must have IBS-C and have a positive breath CH4 test result (> 10 ppm) at
             Screening.

          -  Subject must meet the modified Rome III criteria for IBS-C.

          -  Subject must have an average abdominal pain intensity score of ≥ 3 (scale 0-10)
             reported at Screening and Baseline.

          -  Subject must have an average of fewer than 3 complete spontaneous bowel movement
             (CSBMs) per week.

          -  Subject must agree to refrain from making any lifestyle changes that may affect IBS-C
             symptoms from the time of Screening to the end of the study.

        Exclusion Criteria:

          -  Subject has taken IBS treatments (prescription or over-the-counter), proton pump
             inhibitors, laxatives, antibiotics.

          -  Subject currently has any structural abnormality of the gastrointestinal (GI) tract or
             a disease or condition that can affect GI motility, or any unexplained and clinically
             significant symptoms such as lower GI bleeding, rectal bleeding, heme-positive stool,
             iron-deficiency anemia, weight loss, or systemic signs of infection.

          -  Subject has been diagnosed with or has a family history of familial adenomatous
             polyposis, hereditary nonpolyposis colorectal cancer, or any other form of familial
             colorectal cancer.

          -  Subject reports loose (mushy) or watery stools (Bristol Stool Form Scale [BSFS] score
             of 6 or 7).
      