OK ILL WRITE IT ALL AGAIN LOL
So from what i've learned about male anatomy (I even had a mandatory minor course SPECIFICALLY about homosexual intercourse in both males and females lol) : Yes, during anal sex, it is possible for penetration to extend into the colon, but specifically only into the rectum.
Anatomically speaking; the anal canal (where male penetrative sex normally happens) is about 3–4 cm long and leads directly into the rectum, which is a SECTION of the colon, specifically the section that is the closest to anal canal (about 12–15 cm long). Above the rectum is the sigmoid colon.
Now, during anal sex, if penetration is deep enough, the penis can enter the rectum, but NOT the entire colon. The rest of the colon (beyond the rectum) is much farther inside of the body and cant really be reached through normal penetration (and definitely SHOULDNT be, it would probably be very painful and could cause internal damage).
To go even deeper into it:
How anal sex feels, specifically when penetration reaches into the rectum, varies a lot from person to person. It depends on a lot factors like the receiver's comfort, their anatomy, the giver's technique, etc. There's some general baseline stuff we know from how people describe it and what we actually know about each reproductive organ.
A lot of people describe a deep, internal sensation that feels different from vaginal or anal entrance stimulation. It much less sharp and painful, rather more slow-building and intensely satisfying. Males specifically tend to describe their orgasms through rectal penetration as wavelike and explosive.
The anus has a lotttt of nerve endings (especially the rim), which is what makes it highly sensitive to touch, pressure, stretching, etc. In contrast, the rectum has fewer nerve endings than the anus, and the ones that it does have aren't pain receptors, meaning it normally feels more pleasurable then painful.
Also, males have a prostate, which the rectum provides direct access to. This is because the prostate gland sits just a few inches inside the rectum, toward the front (belly-side), and yall already know the deal with prostate stimulation LOL.
Woah i didn't know all of this :0 It was super interesting!! Thanks for sharing, today i learned something new... And I'm prob gonna use this info somewhere to destroy some stupid grins ಠ◡ಠ
Btw your og message prob got cut bc you used some emoji that the site does not allow/recognize, it causes an error and deletes whatever goes after that emoji. It happened to me before and took me awhile to pinpoint the problem lmao
Hope you have a nice day! <3

I've seen a lot of people confused about the whole colon penetration thing (not rlly the right term lol), so let me yap about the explanation for it from an anatomical point of view.
YAYYYYY (⌒▽⌒) TIME TO PUT MY EXTENSIVE AND KIND OF UNUSUAL AMOUNT OF KNOWLEDGE ABOUT HUMAN BIOLOGY TO USEEEE (didnt spend tuition on medical school for nothing