Anorectal Sensitivity
It is interesting how I always thought this might be the problem but never really looked for a solution or to see if it even was possible. My problem, which is that I believe I am chronically constipated (I always feel there's something in my bowels), started because one day, I stupidly suppressed the urge to empty my bowels. Since then, I barely feel the urge, not even when I get diarrhea.
There's something called Nerve damage, which can actually be caused by holding stools. You no longer feel the urge, until it is just too late and you have to sprint to any bathroom.
Another thing is, I have fbo. Even if it is disgusting, it might be important for this... I can no longer smell my stools, not even after I have a bowel movement. And I usually had an fbo when I really needed to empty my bowels. So there's the problem, I have lost nerve sensitivity and my bowels are never empty, therefore I sometimes have fbo (most part of the time) and I naturally smell like that because I am reaaaally thin (I'm around 164cm and weight 45kg).
If you actually read the whole thing, thanks. And, if you are interested/feel you have the same problem, I'm reading this page that shows you how to restore the nerve sensitivity (I don't think they are selling any product).
http://www.gutsense.org/gutsense/sensitivity.html
Thanks, good luck, and god bless you all.