Does receptive anal sex increase risk of fecal incontinence in older adults?

1. What the major studies actually measured — and what they did not

The U.S. analysis of NHANES 2009–2010 asked adults whether they had ever had anal intercourse and whether they experienced monthly leakage of mucus, liquid, or stool; it found those reporting anal intercourse had higher odds of FI, with different question wording for men and women noted as a limitation ^{[1] [6]}. The large French convenience survey of 21,762 MSM measured FI during the past month and associated higher FI prevalence with RAI ≥1/week, chemsex, and fisting — but it used self-selected, non‑random sampling and only asked about FI in the short term (past month) ^{[2] [7]}.

2. Association ≠ proven cause: why the link is plausible but not definitive

Multiple reports describe an association between RAI and FI, and mechanistic plausibility is discussed in narrative and clinical reviews: penetrative anal practices can injure or fatigue the external anal sphincter and pelvic floor, which could contribute to anorectal dysfunction ^[8]. However, the epidemiologic work is cross‑sectional or convenience‑sample based (NHANES is cross‑sectional; ERAS/MSM survey is non‑random), so these studies cannot prove that RAI causes FI over time or rule out confounding factors such as frequency/intensity of practices, other pelvic pathology, diarrhea, or substance use ^{[1] [2] [7]}.

3. How age and other medical factors weigh in

Available geriatric and gastroenterology reviews stress that aging itself reduces anal resting and squeeze pressures, rectal sensation and compliance — physiologic changes that independently raise FI risk in older adults ^[4]. The 2025 review of new therapies lists advanced age, diarrhea, sphincter damage from obstetric or surgical trauma, pelvic floor abnormalities and neurologic disease as established FI risk factors ^[5]. Therefore, for older adults the incremental contribution of RAI to FI must be interpreted against a background of strong age‑related vulnerability ^{[4] [5]}.

4. Frequency, technique, and co‑factors matter

The MSM survey highlights that risk appears higher with frequent RAI (≥1/week) and with higher‑risk practices such as fisting or chemsex — suggesting dose and modality influence association strength ^{[2] [3]}. Narrative reviews also suggest that pelvic‑floor physical therapy and education might prevent or mitigate anorectal dysfunction attributed to anal intercourse, which implies the relationship is not binary but modifiable by behavior and care ^[8].

5. Limitations and potential biases in reporting

Researchers caution about survey wording differences (NHANES used different sexual behavior questions for men and women), underreporting of stigmatized behaviors, and the cross‑sectional or convenience nature of many datasets — each can bias estimates of both exposure and outcome ^{[1] [6] [7]}. Journal correspondence and reviews underscore that while odds ratios may be larger in some subgroups, overall FI prevalence historically is higher in women than men — so interpretation requires nuance ^[9].

6. Practical takeaway for older adults and clinicians

Available sources support asking about anal intercourse when evaluating FI because it is a potential contributing factor, especially when coupled with frequent or forceful anal practices, chemsex, or prior anorectal trauma ^{[1] [2] [8]}. But clinicians should also prioritize assessment of common age‑related and medical causes (neurologic disease, diarrhea, prior surgeries/obstetric injury) and offer conservative treatments such as pelvic‑floor rehabilitation, dietary measures, and medical management before assuming single causation ^{[4] [10] [8]}.

7. Where the evidence gap remains

Longitudinal, population‑based studies that track RAI practices, technique, frequency, injuries, and later incident FI in older cohorts are not presented in the available reporting; therefore, causality and the magnitude of incremental risk in older adults remain uncertain in current literature (not found in current reporting).