A Phase 3, International, Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel-group Efficacy and Safety Trial of Linaclotide Administered Orally for 12 Weeks to Patients With Irritable Bowel Syndrome With Constipation (IBS-C)

Inclusion Criteria:

1. Patient has signed an Informed Consent Form(ICF).

2. Patient Must not be pregnant or breastfeeding and agree to use birth control

3. Patient meets the colonoscopy requirements defined by the American
Gastroenterological Association guidelines and no clinically-significant laboratory
or physical examination findings;

4. Patient meets protocol-defined criteria for Irritable Bowel Syndrome with
Constipation(IBS-C), including stool frequency, straining, stool consistency,
abdominal pain, and abdominal discomfort criteria

5. Patient meets protocol-defined eDiary completion Compliance and agrees to refrain
from making any new, major life-style changes that may affect IBS-C symptoms

Exclusion Criteria:

1. Recent history of mushy or watery stools

2. Various medical conditions, medical histories, or family medical histories that would
not make the patient a good candidate for the study

3. Patient currently has both unexplained and clinically significant alarm symptoms or
systemic signs of infection or colitis.

4. Surgery to the gastrointestinal tract

5. Usage of prohibited medications