Clinical Trials

Inclusion Criteria

• Able to communicate adequately with the investigator and to comply with the requirements for the entire study
• Meets Rome III criteria for functional constipation as assessed by questionnaires in period 1, i.e., report at least 2 of the following symptoms for last 3 months or more with symptom onset at least 6 months prior to diagnosis
  • < 3 SBMs/week 
  • Hard or lumpy stools ≥ 25% of time 
  • Straining ≥ 25% of time 
  • Sense of incomplete evacuation ≥ 25% of time 
  • Feeling of anorectal blockage ≥ 25% of time 
  • Manual maneuvers to facilitate defecation ≥ 25% of time
• Patients who meet Rome III criteria for irritable bowel syndrome will also be eligible provided they also meet above criteria

Exclusion Criteria

• Current use of opioid analgesics
  • Will be allowed to participate if they have discontinued them for at least 3 days (72 hrs.) before date of screening and are willing to stay off them for the duration of the study
• Current use of anticholinergics (e.g. nortriptyline, amitriptyline, hyoscyamine)
  • Use of low dose tricyclic antidepressants (nortriptyline up to 50 mg/day or amitriptyline up to 25 mg/day ) will be eligible provided no increase in dose during the study period
  • Higher doses or other anticholinergics are eligible if can discontinue medication at least 3 days (72 hrs) before the date of screening and willing to stay off them till the study is complete
• Current use of laxatives (MiraLax, Ex-lax, senna, herbal supplements), linaclotide, lubiprostone, and prucalopride to treat constipation will be eligible if can discontinue the medication at least 3 days (72 hrs.) before the date of screening and are willing to stay off them till the study is complete