OBJECTIVES: To estimate the prevalence of constipation, fecal incontinence (FI), and combined symptoms and to identify shared factors associated with bowel symptoms in older U.S. men and women DESIGN: Population-based cross-sectional study. SETTING: National Health and Nutrition Examination Survey (2005-2010). PARTICIPANTS: Women and men aged 50 and older. MEASUREMENTS: Constipation was defined as hard stool consistency on the validated Bristol Stool Form Scale or stool frequency of fewer than three bowel movements per week. FI was defined as at least monthly loss of solid, liquid, or mucus stool. Combined symptoms was defined as constipation and FI. Multinomial multivarible models adjusted for age, race, socioeconomic status, education, self-rated health, depression, impairments in activities of daily living, and number of comorbidities. RESULTS: Women (n = 3,078) reported higher prevalence of bowel symptoms than men (constipation 11.8% vs 4.7%%, FI 11.2% vs 8.6%, combined symptoms 1.4% vs 0.4%). In adjusted models, women had greater odds of having constipation (odds ratio (OR) = 3.0, 95% confidence interval (CI) = 2.3-3.8), FI (OR = 1.4, 95% CI = 1.1-1.8), and combined symptoms (OR = 4.6, 95% CI = 2.0-10.2) than men. Shared risk factors included poor self-rated health and depression symptoms (constipation: OR = 1.8, 95% CI = 1.4-2.4 and OR = 1.8, 95% CI = 1.0-3.2; FI: OR = 1.6, 95% CI = 1.2-2.2 and OR = 2.3 95% CI = 1.4-3.6; combined symptoms: OR = 2.6 95% CI = 1.5-4.8 and OR = 4.6, 95% CI = 1.3-16.4). CONCLUSION: When defining constipation and FI using validated instruments, women had a much higher prevalence of constipation than men, whereas men had a higher prevalence of FI than constipation. Shared risk factors reflect the negative effect that bowel symptoms have on quality of life.