Most Common Causes of Double Incontinence
The most common causes of combined urinary and fecal incontinence are advanced age (>80 years), diarrhea, neurological disorders (dementia, stroke, spinal cord disease), diabetes mellitus with autonomic neuropathy, and functional/mobility impairment. 1, 2, 3, 4
Primary Risk Factors by Strength of Association
Strongest Independent Risk Factors
- Diarrhea is the single most powerful risk factor for fecal incontinence with an odds ratio of 53, making bowel disturbances the dominant contributor to double incontinence 1, 2
- Advanced age >80 years shows the strongest association with dual incontinence (OR 2.49), surpassing all other risk factors 3
- Depression is strongly associated with dual incontinence (OR 2.28), likely reflecting both neurochemical effects and functional decline 3
Neurological and Medical Comorbidities
- Neurological disease including dementia, stroke, and spinal cord injury directly impairs continence mechanisms (OR 1.84 for dual incontinence) 1, 3, 4
- Diabetes mellitus causes autonomic neuropathy leading to neurogenic bladder and bowel dysfunction, plus polyuria from glycosuria 5, 6, 3
- Functional limitations and restricted mobility are critical risk factors (OR 1.86), as they prevent timely toileting 5, 3
Obstetric and Anatomical Factors
- Multiparity increases risk of dual incontinence (OR 1.66), with higher fetal birth weight further elevating risk (OR 1.24) 3
- Anal sphincter trauma from obstetrical injury or prior surgery damages continence mechanisms 1, 7, 8
- Pudendal nerve damage from childbirth and chronic straining causes progressive deterioration of both urinary and fecal continence 7, 8
- Pelvic organ prolapse frequently coexists with double incontinence, with 49-60% of patients having multiple conditions 9
Secondary Contributing Factors
Modifiable Risk Factors
- Fecal impaction is a frequently overlooked reversible cause, particularly in elderly patients 5, 2
- Medications that affect bowel or bladder function should be systematically reviewed 5
- Higher BMI increases risk (OR 1.1 per unit increase for fecal incontinence), though obesity primarily affects urinary incontinence 1, 3
Additional Associated Conditions
- Stress urinary incontinence itself is an independent risk factor for fecal incontinence (OR 3.1) 1
- History of cholecystectomy (OR 4.2) and rectocele (OR 4.9) are associated with fecal incontinence 1
- Current smoking increases risk (OR 4.7) 1
- Chronic illness burden and comorbidity count correlate with incontinence risk 1, 4
Pathophysiological Mechanisms
- Anorectal dysfunction combined with bowel disturbances (particularly diarrhea and rectal urgency) are the primary mechanisms rather than isolated sphincter defects 1
- Crossed reflexes between bladder, urethra, anorectum, and pelvic floor may explain the comorbidity of urinary and fecal urgency 7
- Collagen disorders and hormonal changes from menopause contribute to pelvic floor weakness 7
Critical Clinical Pitfall
In community surveys, bowel disturbances, rectal urgency, and burden of chronic illness are far more important independent risk factors than obstetric history (forceps use, complicated episiotomy) in older women. 1 This contradicts common clinical assumptions that focus excessively on birth trauma while missing the dominant role of medical comorbidities and bowel dysfunction.