Point-of-care Anorectal Testing to Predict Outcomes With Biofeedback Therapy: Clinical Trial

To prospectively evaluate the clinical utility of baseline anorectal function testing using a point-of-care device in predicting response of chronically constipated patients to physical therapy biofeedback training.

Chronic constipation affects 10-20% of the US population and can impact quality-of-life to a similar degree as congestive heart failure or rheumatoid arthritis. Notably, 700,000 individuals present to the emergency department for constipation each year in the US and $10 billion is spent annually on laxative therapy. For symptomatic chronic constipation refractory to fiber or laxative therapy, clinical practice guidelines recommend physiological testing to identify abnormalities in anorectal function as the next step5. Abnormal anorectal function testing (including anorectal manometry and balloon expulsion testing) suggests an evacuation disorder, the most common of which is dyssynergic defecation or dyssynergia. Identification of patients with an evacuation disorder as a primary driver of constipation is important since therapy can then be targeted.

To enable standardized, accessible chronic constipation testing for general gastroenterologists, the investigators invented an office-based, point-of-care Rectal Expulsion Device (RED). By incorporating RED into a general gastroenterologist's outpatient visit, chronically constipated individuals with abnormal anorectal function can be identified quickly and directly triaged to biofeedback therapy. Thus, RED offers the possibility of disrupting the current treatment paradigm by enabling an initial biomarker based strategy for patients with chronic constipation. Before such a process of care can be realized, there is a critical need for prospective data to determine the best setting for anorectal function testing in the clinical care pathway. The investigators aim to prospectively evaluate the clinical utility of baseline anorectal function testing using RED in identifying chronically constipated patients with evacuation disorders who would benefit from biofeedback therapy.

The investigators will conduct a 12-week clinical trial enrolling individuals with laxative-refractory chronic constipation. All study participants will undergo RED and traditional lab-based testing at baseline, followed by a standardized three-session biofeedback protocol for dyssynergia.

Eligibility Criteria:
Inclusion Criteria:

* individuals aged 18-80 with a body mass index of 18 to 40 kg/m2 and a primary ICD-10 diagnosis for constipation (K59\*) or referral for constipation.

  * Does the patient meet Rome IV criteria for functional constipation (FC)?
  * Does the patient report that fiber or laxative therapy has been ineffective to treat constipation in a documented treatment trial for at least two weeks prior to screening?
  * Patient is already scheduled for anorectal manometry and physical therapy as part of routine care.
  * The patient must agree to maintain their current dietary fiber intake and osmotic or bulk-forming laxative regimen (if any) throughout the trial
  * The patient must agree to use stimulant laxatives (such as magnesium citrate \[Milk of Magnesia\], senna or bisacodyl \[Dulcolax\]) NO MORE THAN two days per week during the trial
  * Patient must be able to participate in physical therapy for biofeedback
  * Individuals must have health insurance coverage to undergo anorectal function testing and biofeedback therapy as part of their non-study routine clinical care

Exclusion Criteria:

* adults unable to consent, individuals who are not yet adults, pregnant women, and prisoners, as they would be unable to reasonably comply with physical therapy within the duration of the study and would thus undergo unnecessary testing.
* Patient must NOT have tried biofeedback therapy or undergone anorectal manometry previously
* Patient must NOT report prior SURGERY involving the colon or rectum (including surgery for anal fissure, rectal prolapse)
* Patient must NOT recent opioid use within 30 days of enrollment
* Patient must NOT report a neurodegenerative condition (i.e. Parkinson's disease, dementia, multiple sclerosis, spinal cord injury) or uncontrolled inflammatory bowel disease
* Patient must NOT have used linaclotide (Linzess), lubiprostone (Amitiza), plecanatide (Trulance), tegaserod (Zelnorm) or prucalopride (Motegrity) within 30 days prior to enrollment. Patients MUST agree not to use these agents during the trial