I measured my rectum by putting the end of a toothbrush into my ass. I managed to put 5 inches of it up my rectum then i hit a wall like barrier. I believe it's the sigmoid colon which is right before the rectum. I can't go any deeper or put anything up my colon. I usually feel alot of pressure and it kinda hurts when i try to go deeper! Any feedback or similarities by any chance?