This study will be conducted as a multicenter, randomized, double blind, placebo controlled trial to evaluate the tolerability of MHS 1031 and tolerability of the formulated placebo. The study consists of a screening phase to establish eligibility and baseline values, followed by 3 distinct study periods.

Subjects with CIC will be determined eligible for the study based on modified Rome IV criteria during a 2 week Screening Phase. Approximately 200 subjects with CIC who meet all eligibility criteria will be randomized in a 1:1 ratio, with equal numbers of each in each successive group of 50 subjects, to receive either MHS 1031 [1 g (1.4 ml) per day] or 1.4 ml of placebo (1:1) for 8 weeks (Product/Placebo Phase). Upon completion of the 8 week Product/Placebo Phase, Subjects will enter a 4 week open label Product Phase, during which all subjects will receive MHS 1031. Subjects who complete the study will enter a 2-week Follow-up Phase, during which subjects will take neither placebo nor MHS 1031.

During the study, tolerability will be assessed on the basis of Patient Reported Outcomes (PRO questionnaires), concomitant medication assessments, and assessment of adverse events. Tolerability is defined as no overall worsening of constipation measurement scores after 8 weeks of taking the product or the placebo compared to baseline scores.