B. R. Simon Rosser, PhD, MPH & Syed Noor, PhD Enema use among men who have sex with men: A behavioral epidemiologic study with implications for HIV prevention B. R. Simon Rosser, PhD, MPH & Syed Noor, PhD HIV/STI Intervention & Prevention Studies (HIPS) Program Division of Epidemiology & Community Health School of Public Health University of Minnesota 21st World Congress on Sexual Health Porto Allegre, Sept 21-24, 2013

Introduction Very little is known about enema use among MSM. Studies have found it associated with both STI and HIV acquisition -possibly due to damaging the anal epithelium. Research on microbicides for MSM make studying enema use particularly relevant.

Enema Use = Rectal Douching Variety of commercial and home products Saline, H2O, and home mixes (e.g., soap)

Enema Use = Rectal Douching Variety of practices in inserting the enema to flush the rectum before and/or after sex But we lack empirical data of what and how enemas are being used for anal sex in MSM.

Methods As part of a wider study, we conducted a sub-study on enema use. Participants: 4,992 MSM in 16 US cities, recruited from two large gay websites Typical online MSM sample: young, white (non Hispanic), well-educated, urban, liberal, in a relationship (53%), and HIV- (89%) Procedures: Online surveys in 2011.

Selected Key Results (N=4992 U.S. MSM) Ever: Frequency of behavior: 52% MSM Current: 35% reported douching (88% before receptive anal sex and 28% after receptive anal sex)

Selected Key Results (N=4992 U.S. MSM) Ever: Frequency of behavior: 52% MSM Current: 35% reported douching (88% before receptive anal sex and 28% after receptive anal sex)

Selected Key Results When do you douche before sex? (N=2,221 douche before MSM) 13% mainly before unprotected RAI 70% before any RAI 17% only before protected RAI When do you douche after sex? (N=704 douche after MSM) 40% mainly after unprotected RAI 49% after any RAI 10% mainly after protected anal sex => Douching appears to be used as an HIV prevention strategy

Key Results Type of products used: When? Most (66%) douche with water 24% add salt, soap or bacterial products 30% use commercially available products Race/ethnicity differences found on products used When? Before sex: Mean 60 minutes (IQR:30-120 min) After sex: Mean 30 min (IQR: 15-60 min)

Why do MSM douche? (N=2,597 US MSM “douchers” online surveys, 2011) Reason given for douching before sex % Sex preparation 9 Hygiene/Cleanliness (to avoid feces) 64 Partner considerations 4 To clean out anything which might be transmissible 2 To avoid embarrassment 16 To get excited for anal sex 1 To flush out any left over ejaculate To increase pleasure 3 Other reasons Reason for douching after sex 55% Transition from sex 28% HIV/STI prevention 13% Other 5%

Reasons given for NOT douching (N=4,301 US MSM online surveys, 2011) We also asked MSM who don’t douche, why they don’t: Reason for NOT douching before sex % Don’t engage in anal sex 20 Don’t like it, find it painful or uncomfortable 6 I prefer sex to be spontaneous 46 I do not mind/prefer anal sex being “dirty”/”natural” 10 HIV/STI prevention 4 I don’t know about douching 27 Other

Multiple logistic regression models Who is more likely to douche and when? Person variables: Higher income (p<.005) Being a man of color (p<.005) Being HIV positive (p<.001) Being diagnosed with an STI, last 12 months (p<.01) Behavioral variables: Meeting partners online and offline (p<.001) Being “versatile” (p<.001) or a “bottom” (p<.001) Having 2+ unprotected anal sex partners (p<.001) were each associated with recent enema use after adjusting for other variables.

Discussion Significance: To the best of our review, this is the first large study of enema use among MSM to be conducted.

Key Conclusions 1-in-3 MSM douche regularly – this behavior is very common Douching appears closely associated with HIV risk behavior, HIV+ status and STI diagnosis. HIV+ MSM and STI+ MSM were more likely to report adding soap or antibacterial product to water before douching. Since lab studies have shown that water (and soap) damage the epithelium, this is potentially problematic.

Key conclusions 13% use enemas post-coitus for HIV prevention 27% non-users state they do not know about enemas Need for education

Future Research Recommendations Douching with water or water and soap may be a particular concern if it increases damage to the epithelium. Development of a non-damaging, non-water based enema specifically for use before anal sex is recommended.

Implications for HIV prevention education Risk elimination (“just say no”) – unlikely to be successful Risk reduction (education on safer enema use) – needs science to identify the least toxic or non-toxic substance (e.g., iso-osmolar based enemas) Caution: advocating for water based lubricant but warning about water based enemas appears contradictory

Limitations Cross sectional study so causality and temporality cannot be assumed Socially-sensitive topic where all data are self-report; rates are likely under-estimates Sample is a large convenience sample not a representative one – generalizability of findings are not known.

Acknowledgements The SILAS grant is funded by NIAAA (AA01627001). These results are in press: Noor, S.W., Rosser, B.R.S. (2014). Enema use among men who have sex with men: A behavioral epidemiologic study with implications for HIV/STI prevention. Archives of Sexual Behavior, in press. The SILAS grant is funded by NIAAA (AA01627001). (PI: Rosser). Investigators, Staff and Consultants: B. R. Simon Rosser, PhD Sonya S. Brady, PhD Michael Oakes, PhD Rhonda Jones-Webb, PhD Keith Horvath, PhD Gunna Kilian, BA Syed W. Noor, PhD Joe Konstan, PhD Derek Smolenski, PhD, MPH Dale Carpenter, JD Richard Weinmeyer, Mphil Katherine Nygaard, MPH J. Michael Wilkerson, PhD, MPH

B. R. Simon Rosser, PhD, MPH, LP rosser@umn.edu Thank you and wishing you good sexual health! B. R. Simon Rosser, PhD, MPH, LP rosser@umn.edu