understanding mechanisms of normal and disordered defecation

Conditions: Constipation

Summary: 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.

Eligibility criteria:
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.