Understanding Mechanisms of Normal and Disordered Defecation

Understanding Mechanisms of Normal and Disordered Defecation

Researchers are trying to better understand why constipation occurs and improve the tests for diagnosing these conditions.

Study includes a screening visit and a study day. During the initial screening visit for this study, subjects will complete three (3) questionnaires about their bowel symptoms, overall health, and anxiety and depression. A blood sample (about 4 tablespoons) will be drawn to study the relationship between genes and certain bowel habits. Subjects will be asked to provide a single stool sample to look at the bacteria in the stool.

Before the study, subjects will receive 1 to 2 Fleet's enemas to clean the rectum. After receiving the Fleet's enema (administered through a small plastic tube in the rectum), a swab attached to a small rectal catheter will be used to brush the lining of the rectum and obtain a stool specimen. Then, rectal and anal pressures will be measured by placing a small catheter (plastic tube) in the rectum, and withdrawing it slowly. Rectal sensation will be measured by inflating a small balloon in the rectum.

There are 2 procedures (rectal barostat study and fecomanoflowmetry), each of which lasts approximately 90 minutes. During the rectal barostat study, contractions will be recorded with a balloon inserted into the rectum and inflated. After the barostat study is completed, your rectum will be filled with a small amount of paste. Two thin catheters will be inserted into the anus to measure pressures and electrical activity (electromyography or EMG). Then, you will be asked to sit on a commode, contract (squeeze) your anal muscles, blow into a balloon, and expel the paste into the commode.

Inclusion Criteria

• Male and female volunteers aged 18-80 years.
• Able to provide written informed consent before participating in the study.
• Able to communicate adequately with the investigator and to comply with the requirements for the entire study.
• Individuals with chronic constipation for 1 year, with 2 or more of the following symptoms for 3 months or longer: <3 bowel motions/week, straining ≥ 25% of time, hard or lumpy stools ≥ 25% of time, anal digitation ≥ 25% of time, incomplete evacuation ≥ 25% of time, feeling of anorectal blockage ≥ 25% of time.
• Able to provide written informed consent before participating in the study.
• Able to communicate adequately with the investigator and to comply with the requirements for the entire study.

Exclusion Criteria

• Clinical evidence of significant cardiovascular, respiratory, renal, hepatic, gastrointestinal, hematological, neurological, psychiatric or other disease that may interfere with the objectives of the study and/or pose safety concerns.
• Current symptoms of a functional gastrointestinal disorder assessed by questionnaire.
• Putative risk factors for pelvic floor trauma: i.e. six or more vaginal deliveries, birthweight >4500gms (macrosomia), or known 3rd or 4th degree perineal tear.
• Medications that are likely to alter gastrointestinal motility: e.g., opiates and anticholinergic medications; a stable dose of thyroxine and low doses of tricyclic agents (e.g., up to amitriptyline (50 mg daily).
• Active rectal inflammation, cancer; perianal sepsis; history of pelvic radiation, rectosigmoid surgery or inflammatory bowel disease.*
• Anxiety or depression as assessed by the Hospital Anxiety and Depression Questionnaire.
• Pregnant women, prisoners and institutionalized individuals.