Latest Update: May 2024


These pages are a continuing work in progress and provide different points of view on the many issues surrounding the use of butt toys and butt play in general. From the start, SquarePegToys® has been a trusted source of information on playing safely and healthfully in this extreme sport of ass play and fisting.  Many of you have been asking over the years for advice and asking about resource material. The information within these pages is a response to that and is updated as new information comes available. This is only intended to inform and should not ever be considered instructions for what you should do specifically as there are wide ranges in anatomical differences and abilities that will make your journey unique to yourself.

I am not a medical professional, rather I come to this with over 30 years of healthy ass play experiences, and added contributions that others have shared with me over that time, as well as a strong curiosity to seek out research in the realms of intestinal anatomy.  Only you know where you are on your journey and what you are capable of. Your physiology is unique to you, you just have to find out what pushes your buttons in a safe and fun manner.

Major updates to these pages in May 2024, reflect new research that is being done in the area of colonoscopies in an effort to automate that process.  Extensive mapping and measuring of the various segments of the lower colon and rectum are proving to be very helpful when applied to our sport.  References are provided below and sited where appropriate.


All of the information contained in these pages will be greatly benefited by how well you are in tune with your body and how well you are able to put your mind at ease and focus on your play. Personally, I have always felt that large dildo play and fisting was a lot like a meditative experience, noticing that my best play sessions came when I was most in tune with my Self and able to focus clearly on what I was feeling. Anything that could cloud my mind or disrupt my body’s own natural rhythm more often than not got in the way of a good time.

Extreme Sport

As a community we regard playing with large dildos and fisting as an Extreme Sport and as such, being well informed and following certain guidelines will help to minimize the risks. Having the right equipment at hand is also important, as is working within a certain set of guidelines to help ensure safety. As with any extreme sport, risk of personal injury always exists, but by taking the necessary precautions we can hope to minimize that risk to an acceptable level. Accidents can and do happen. Not pushing your body beyond what it is capable of at that moment, or, your timely reaction to injury were it to occur, could greatly minimize your level of risk and even save your life someday.


I have not intentionally published copyrighted information, providing links to its home on the web instead wherever possible, and proving citations, if I have inadvertently done so, please let me know. The information herein comes from a long personal experience both directly and indirectly, as well as relevant research articles. All of what is here is presented in the spirit of community, sharing and the well-being of us all. Do not view this a prescription for, nor a guarantee of, injury free play. In the case of direct contributions I have left out names for reasons of protecting anonymity.

Reference Material

Alazmani, A. Hood, D. Jayne, et al, “Quantitative Assessment of Colorectal Morphology: Implications for Robotic Colonoscopy”, Medical Engineering & Physics, 38 (2) pp. 148-154 (2016). ISSN 1350-4533.

J.Painter, D.B. Saunders, G.D. Bell, C.B. Williams, R. Pitt, and J. Bladen, “Depth of Insertion at Flexible Sigmoidoscopy: Implications for Colorectal Cancer Screening and Instrument Design”, Endoscopy, 31 (3) pp. 227-231, (1991).

G.A. Lehman, D.M. Buchner, and J.C. Lappas, “Anatomical Extent of Fiberoptic Sigmoidoscopy”, Gastroenterology, 84: pp. 803-8, (1983).

A.Shafik, S. Doss, S. Asaad, Y.A. Ali, “Rectosigmoid Junction: anatomical, histological, and radiological studies with special reference to a sphincteric function”, Int Journal of Colorectal Dis, 14: pp. 237-244, (1999).