This study evaluates the efficacy and safety of a single injection of iltamiocel (300 x 10^6 cells) compared to a placebo in the reduction of fecal incontinence episode frequency in adult female participants with chronic fecal incontinence and a history of obstetric anal sphincter injury. Half of the participants will receive iltamiocel (injections with cells) and the other half will receive placebo.

Chronic fecal incontinence (FI) is the recurrent unintended passage of mucus and/or liquid or solid stool for at least 6 months. Iltamiocel is an investigational cell therapy product that involves a medical procedure in which a participant's own muscle cells are collected, processed, and then injected into the tissues of the external anal sphincter.

This is a double-blind randomized study, which means neither the participant, nor the study doctor will know which treatment group the participant will be in. Participants who are randomly chosen to receive injection with placebo will have the option to receive an injection with their cells after completion of the blinded portion of their study participation (12 months).

Inclusion Criteria:

• Adult female ≥ 18 years of age who has primary symptoms of fecal incontinence (FI) for at least 12 months.
• History of obstetric anal sphincter injury (e.g., episiotomy, perineal tear).
• Failed conservative treatment (e.g., dietary modification, antidiarrheal medications, pelvic floor muscle training, biofeedback) for at least 6 months prior to enrollment.
• Must be willing and able to comply with the study procedures, be mentally competent and able to understand all study requirements, and must agree to read and sign the informed consent form prior to any study-related procedures.

Exclusion Criteria:

• Has an implanted stimulation neuromodulation system (sacral or tibial) and symptoms are unstable as determined by the physician.
• Is pregnant or planning to become pregnant within the next 2 years.
• Has known rectal sensory dysfunction (e.g., hypersensitivity or hyposensitivity).
• Has an obstetric anal sphincter injury (e.g., episiotomy, perineal tear) within 1 year previous to study enrollment.
• Patient BMI ≥ 38.
• Has a history of cancer in the colorectal or pelvic organs within 5 years prior to study enrollment.
• Any cancer that has undergone treatment within the past 12 months.
• Has an established diagnosis of inflammatory bowel disease (Crohn's disease, ulcerative colitis) or current intestinal stoma.
• Has grade III/IV hemorrhoids.
• Has chronic diarrhea at the time of Screening.
• Has chronic constipation at the time of Screening.
• Has significant pelvic floor prolapse, significant genitourinary prolapse beyond the introitus, significant symptomatic rectocele, or evidence of significant rectal evacuation disorder leading to post-defecatory leakage.