>>35473Aneros offers numerous products, and they may have varying maximum girth.
Regarding girth alone, here are DOIs of pertinent studies quoted in the 20190425 revision of Anorectal Risks 1
>>9329 & Anorectal Risks 2
>>9317 posted here: 10.1097/dcr.0b013e3182a18e87 & 10.1136/gut.37.1.4 & 10.1055/s-0031-1272825
The text for those images along with the latest revision can be found below. All of the URLs are archived on archive.is and web.archive.org.
Anorectal Trends, Risks, and Anatomy compilation
20210101
https://paste2.org/EUgnnPhw https://paste.ee/r/HWypC/020190425
https://paste2.org/nHbf1kxJ https://pastebin.com/AWuuf9GvAlso relevant:
"The authors [of "Anal Intercourse and Fecal Incontinence: Evidence from the 2009-2010 National Health and Nutrition Examination Survey." The American Journal of Gastroenterology. 2016 Feb; 111(2): 269-74. PMID 26753893. doi:10.1038/ajg.2015.419.] point out that the internal anal sphincter muscle is responsible for maintaining the resting pressure of the anus (i.e., keeping the anus closed, and keeping stool inside where it belongs), and previous studies show that men who receive anal intercourse have lower anal resting pressure. They postulate that anal sex may simply dilate and stretch the anal sphincter muscle and eventually cause damage to the muscles themselves, and/or cause sensory nerve damage leading to loss of sphincter sensation and control."
… "For reference, the diameter of an adult colonoscope, which is designed to be inserted into the anus, is 0.5 inches (Olympus CF-HQ190L, 12.8 mm OD). This is roughly one-third the diameter of the average erect penis [citing a British Journal of Urology study: PMID 25487360]."
https://www.kevinmd.com/blog/2016/Post too long. Click here to view the full text.