BACKGROUND: The prevalence of receptive anal intercourse (RAI) is increasing. A few studies, with heterogeneous designs, have investigated the associated risk of fecal incontinence (FI). AIM: The primary objective of this study was to determine FI prevalence in a population of men who have sex with men (MSM) engaging in RAI. The secondary objective was to identify risk factors for severe FI. METHODS OUTCOMES: An online survey of 24,308 MSM was performed in 2019. Demographic and socioeconomic data were collected, together with information about RAI sexual practices, and FI defined by: "During the last month, have you experienced any involuntary leakage of stools?" RESULTS CLINICAL IMPLICATIONS: In total, 1,734 (8%) of the 21,762 participants reported FI. Mean age was 35.3 years. The prevalence of FI was correlated with RAI frequency: 12.7% (if RAI ≥ 1 /wk) versus 5.7% (if no RAI). In multivariate analysis, the factors associated with FI were age (OR: 1.01), low socioeconomic status (OR 1.32 to 1.40), HIV-seropositivity (OR: 1.78), high RAI frequency (OR: 1.64), chemsex (OR: 1.67) and fist-fucking (OR: 1.61). STRENGTHS AND LIMITATIONS: Main strengths of our study are population size and assessment of detailed modalities of sexual practices. Main limitations are the use of a convenience non-random sample and the assessment of FI only during the past month. CONCLUSION: This study of a large MSM population, highlights risk factors for FI among RAI practices: RAI ≥ 1 /wk, chemsex, fist-fucking, low socioeconomic status. Garros A, Bourrely M, Sagaon-Teyssier L, et al. Risk of Fecal Incontinence Following Receptive Anal Intercourse: Survey of 21,762 Men Who Have Sex With Men. J Sex Med 2021;18:1880-1890.