© 2020, The International Urogynecological Association. Introduction and hypothesis: To evaluate change in fecal incontinence symptom severity after 8 weeks of darifenacin therapy in patients with double incontinence-urgency urinary incontinence (UUI) and fecal incontinence. Important secondary outcomes included fecal incontinence symptom distress and impact on quality of life, fecal incontinence episodes, global impression of improvement and overactive bladder symptom distress and impact. Methods: Prospective open-label cohort study of women presenting primarily with UUI, diagnosed with double incontinence and electing antimuscarinic therapy for UUI. Women ≥ 18 years with moderate or greater bothersome UUI and fecal incontinence of liquid/solid stool with St. Marks (Vaizey) score ≥ 12 were included. Subjects were treated with darifenacin 15 mg daily for 8 weeks. The primary outcome was change in fecal incontinence symptom severity using the St. Marks (Vaizey) score after 8 weeks. Sample size was based on the minimally important difference of the St. Marks, −5, and standard deviation, ± 8.5; 30 subjects provided 80% power and type I error of 0.05, including a 15% attrition rate. Results: Thirty-two women were consented with mean baseline St. Marks (Vaizey) score of 18.0 ± 3.0. Mean age was 66.5 ± 10.3 years. Twenty-eight subjects (29/32, 87.5%) completed assessments. St. Marks (Vaizey) score significantly improved from 18.0 to 11.0 [mean difference − 7.0, 95% confidence interval (CI): −8.7, −5.3], and 19 subjects (19/32,67.9%) met the minimally important difference. Statistically significant improvements were also noted in fecal incontinence frequency, quality of life, and overactive bladder symptom bother and quality of life (all p < 0.01). Conclusions: Darifenacin can be considered a highly effective early intervention in women suffering from double incontinence. Clinical trial registration: Bladder Antimuscarinic Medication and Accidental Bowel Leakage (BAMA), https://clinicaltrials.gov/ct2/show/NCT03543566, NCT03543566.