I have a collection of over 50 colon/rectal tubes in just about every length and size imaginable, and have experimented with them ALL. My conclusions:
With standard "orange" rubber (actually plastic) colon tubes, longer is better, but only IF YOU can actually get them all the way in without kinking.
Before the internet, for many years the only colon tubes I could find were F22 to F32 in a 30" legenth. They worked well, but I eventually wanted to get the enema highter up into my colon, so I spliced two F22 30" colon tubes together, and could get them all the way up my colon most of the time (but not always). That gives a really EXCELLENT HIGH ENEMA!
Via the internet I came across an Indian manufacturer and ordered a sample of ALL sizes of 50" colon tubes from F20 through F48, and tried them ALL. To my surprize, the smaller F sizes were considerably less likely to kink and go all the way in (as measured by where the fluid is asctually filling up the colon). Since smaller diameter, long colon tubes seemed the "best", and were not readily available on the internet, I considered "going into the business" - only to find out the minimum orders from India were too large for my expectations, plus my impression that most people find the larger F sizes much "sexier" (I certainly feel that way!) and there probably is not much of a market for the smaller F sizes, ever if they tend to work better.
Since the introduction of SILICONE COLON TUBES, I have switched to them almost exclusively. They are smoother and less likely to kink, in part due to a relatively thicker internal wall. They're expensive, but I think well worth it. They are also easier to keep clean.
I use an F30 30" silcone colon tube for "regualar" use, and also enjoy a 48" F40 silicone colon tube. They are both available from www.optimalhealth.com as well as other places on the web.
Bottoms UP ! 😃