A multicenter study to evaluate the effectiveness and safety of multiple dosage regimens of an investigational drug for the treatment of constipation due to prescription pain medication in subjects with cancer pain. The study will require five visits over a five-week period.

Inclusion criteria:

• Participant is in any stage of cancer but has a minimum life expectancy of at least 3 months at the time of the Screening Visit.
• Participant is taking opioid therapy for persistent cancer pain.
• Participant meets the definition of opioid-induced bowel dysfunction as follows: Since starting opioid therapy, the subject has had decreased bowel movement (BM) frequency and at least one of the following constipation symptoms [sensation of incomplete evacuation, difficulty in expelling stool (straining), hard stools (abnormal stool consistency)].
• Participant understands the procedures, agrees to participate in the study, and has signed and dated the informed consent form prior to the initiation of any study-related activities, including discontinuation of pre-study laxative regimen or other prohibited medications.
• Participant is able and willing to comply with a daily paper diary and is capable of completing paper questionnaires at study visits.

Exclusion criteria:

• Participant is pregnant or lactating, or planning to become pregnant.
• Participant is not ambulatory.
• Participant has participated in another trial with an investigational drug (unapproved), device or procedure within 30 days of the Screening Visit.
• Participant is unable to eat, drink, take/hold down oral medications.
• Participant is taking opioids for the management of drug addiction.
• Participant is unable or unwilling to discontinue the use of and/or refrain from using laxatives of all types and formulation at the Screening Visit and throughout the entire study.
• Participant has severe constipation that has not been appropriately managed such that the subject is at immediate risk of developing serious complications of constipation. This would include a subject who has reported no bowel movement for 7 consecutive days prior to the Screening Visit.
• Participant with gastrointestinal or pelvic disorders known to affect bowel transit, produce gastrointestinal (GI) obstruction, or contribute to bowel dysfunction.
• Participant is currently taking vinca alkyloids or plans to take vinca alkyloids during the study.
• Participant is currently undergoing abdominal radiation therapy and/or plans to undergo abdominal radiation therapy during the study.
• Participant is human immunodeficiency virus (HIV)-infected, has active hepatitis (any subtype including ongoing chronic hepatitis B), or has ever been infected with hepatitis C.