Constipation is a common digestive disorder. After excluding dietary factors, drugs and
other secondary causes, at least three broad pathophysiologic subtypes are recognized-
dyssynergic defecation, constipation-predominant irritable bowel syndrome (IBS-C) and slow
transit constipation (STC), all predominantly affect women and elderly. Many patients also
demonstrate abnormal rectal perception with both rectal hyposensitivity and hypersensitivity
being common. Recent surveys show that most constipated patients are dissatisfied with
current therapy. Also, constipated patients showed significant psychological dysfunction and
impaired quality of life. OBJECTIVE: To investigate a novel biofeedback technique of
improving rectal hypersensitivity.
METHODS: A large compliant balloon attached to a barostat was placed in the rectum in 8
patients with rectal hypersensitivity (urgency/pain threshold <30 mm Hg). Sensory
deconditioning was performed by incremental balloon distensions (1-2 mmHg) until normal
thresholds were reached.
All patients must fulfill the diagnostic criteria for IBS-C (Rome III) as defined below
and have rectal hypersensitivity (see below).
- Patients must report recurrent abdominal pain or discomfort for at least 3 days per
month in the last 3 months with two or more of the following symptoms:
- Improvement with defecation; and/or
- Onset associated with a change in frequency of stool; and/or
- Onset associated with a change in form (appearance) of stool
- No structural diseases
- On a diary:
- Pain/discomfort for at least 2 days/week;
- No loose or watery stool <25% of bowel movements.
- Patients with mixed-IBS.
- Patients currently on SSRI or MAO inhibitors. Patients on stable doses of other
antidepressants will be included provided the dose is unchanged during study.
- Patients taking drugs that are constipating, (e.g.; calcium channel antagonists will
either be excluded or drug discontinued)
- Patients with co-morbid illnesses; severe cardiac disease, chronic renal failure or
previous gastrointestinal surgery except cholecystectomy and appendectomy.
- Neurologic diseases e.g.; head injury, epilepsy, multiple sclerosis, strokes, spinal
- Impaired cognizance (mini mental score of < 15) and/or legally blind.
- Pregnant or likely to conceive during the course of the study. Women with potential
for pregnancy must be willing to use contraceptive measures during the study. Urinary
pregnancy tests will be performed on such women prior to any radiologic procedures.
- Hirschsprung's disease.
- Alternating constipation and diarrhea (22).
- Ulcerative/Crohns colitis.
- Previous pelvic surgery, rectocele/bladder repair, radical hysterectomy, anal
- Rectal prolapse or anal fissure.
Satish SC Rao, MD, PhD
University of Iowa
Satish SC Rao, MD, PhD