Fecal Incontinence Treatment (FIT) Study

This is an unmasked, multisite, randomized, parallel group study comparing the effectiveness of two treatments [BIO and INJ] for moderate to severe FI:

1. Baseline: Participants will keep a daily symptom diary for two weeks to (a) document that they meet the minimum frequency required for inclusion in the study and (b) provide a reference value for assessing treatment response at the end of EMM and at 3, 6, 12, and 24 months follow-up points.
2. EMM: All participants meeting inclusion criteria will first be treated with EMM for 4 weeks. The key components of treatment are patient education about the basic physiological mechanisms for defecation, diet and medication to normalize stool consistency, and pelvic floor exercises taught by printed instructions. Additional goals of the EMM protocol are (a) to ensure that participants randomized to BIO or INJ meet the accepted criteria for these treatments by failing to respond to EMM, and (b) to document the efficacy and the durability of systematically applied, optimized EMM. Patients who are responders to EMM will be followed up 3 months later; those who remain responders will be continued on EMM and followed for the remaining 24 months of the study. However, those who are no longer responders to this conservative treatment after 3 months will be invited to be randomized to BIO or INJ and all outcome measures will be assessed at 3 months from initiation of the treatment arm to which they are randomized. They will be pooled with other patients randomly assigned to the same treatment for the primary analyses and will be assessed at 6 months.
3. Randomly assigned treatment: Each participant who fails the EMM will be randomly assigned to BIO or INJ and treated as follows:

• BIO will consist of 5-6 one-hour training sessions spaced at weekly intervals. These will occur in the first 5-6 weeks of treatment. Treatment approaches will include strength training in all participants, sensory training for participants with hyposensitivity, and/or urge-resistance training for participants with hypersensitivity to the sensations caused by rectal distention. Home exercises will be assigned to participants to practice these skills, and these will be guided by a brochure.
• INJ will include a preparation for treatment and a treatment visit. The preparation will involve prophylactic antibiotics for the day of the procedure and minimal restrictions on food intake. On the day of the procedure, a physician will inject 1 ml of dextranomer into each of 4 quadrants of the rectum proximal to the dentate line. Ten seconds will be allowed to pass before the injection needle is withdrawn to minimize drainage of the dextranomer. The participant will be scheduled to return in 6 weeks for possible repeat injection of a second 4 ml of dextranomer. At this second appointment, if FI has improved by 75% or more compared to baseline, the participant will be continued without a second injection. However, if the rate of FI is greater than 75% of baseline, the participant will be offered a second injection of dextranomer.

1. Combination therapy: The primary assessment of efficacy is at 3 months following the first treatment visit completed, and participants who have not achieved at least a 75% reduction in FI frequency compared to baseline will be classified as treatment failures; they will be invited to choose the treatment to which they were not randomized or SNS as an adjunctive treatment for the remaining months of the study. One reason for this is to increase the likelihood that participant will consent to be randomized despite possibly having a priori preferences for one of the two treatments. Thus, the participants who add a second treatment and continue to be monitored up to 24 months will constitute a pragmatic clinical trial (i.e., the study design for these participants going forward emulates the clinical situation in which patients who have an unsatisfactory response to a treatment are offered a new treatment or an ancillary treatment).
2. Long-term follow-up: An intention-to-treat analysis of efficacy will be carried out at 6, 12 and 24 months. For these analyses, all participants randomized to treatment will be included in the analysis. All treatments will continue to be active. The bulking agents injected in the INJ treatment will remain in place. For BIO, participants will be encouraged to continue to practice pelvic floor exercises and enhanced awareness of rectal sensations following the initial training period. Participants who withdraw from the study or who fail treatment at 3 months will be evaluated as treatment failures in follow-up analyses of efficacy. Data will be collected from participants who add an alternative treatment at 3 months, but these data will not be considered in this analysis. Safety data will be collected at every visit. Participants who are responders at 3 months will continue to monitor symptoms for an additional 21 months (2 years total) whereas participants who are non-responders at 3 months will be retained as treatment failures in the long-term analysis of the comparative effectiveness of the BIO and INJ treatments. For longitudinal assessments of safety, cost, and secondary outcomes such as quality of life and FI severity scales, statistical models will include data from follow up time points through 24 months.
3. Adjust for Expectation of Benefit: In a trial comparing behavioral and medical therapy, participants cannot be masked. The validated Credibility/Expectancy Questionnaire was developed to assess the patient's expectation of benefit after initial exposure to treatment and was used in previous studies to determine whether there is equipoise between the active and control conditions in behavioral treatment trials.
4. Characterization of Enhanced Medical Treatment - Durability of improvement and predictors of response: The primary purpose of treating all participants with an EMM run-in is to be able to exclude participants who do not require more costly interventions. However, the investigators will take advantage of the opportunity provided by this run-in study to identify predictors of response to EMM and to assess the durability of improvements. EMM will not be "usual care" but will follow a written protocol that is intended to optimize EMM, which is why this is labelled enhanced medical management. Participants who are treatment responders at the end of the EMM run-in will be scheduled for 3-month follow-up, and those who are no longer treatment responders at 3 months follow-up will be offered an opportunity to be randomized to one of the 3 treatments at this point. However, those who remain responders to EMM at 3 months follow-up will continue to be followed for an additional 21 months. All participants, regardless of their outcomes at the end of EMM, will be encouraged to continue using the treatment approaches learned during the EMM phase.

Each participant will be studied for 24-27 months after completing the month of EMM and the anticipated duration of the study is 4.5 years from first enrollment to completion of the last participant. Approximately 285 adult participants, both male and female, will be recruited for EMM to ensure that 194 participants who did not benefit from EMM will be available for randomization to the two treatment arms (97 per treatment arm). The participants may be referred by clinicians or may respond to posted advertisements about the study.