I am a colon hydrotherapist in Missouri, USA and have been for 4 years.
I don't see the inside of people's colons, only what comes out.  I do
know that some people have a lot of poop come out, and some people
don't.  One recent patient is a woman who has many ailments besides
chronic constipation and is on over a dozen medications.  When I first
started seeing her she was scheduled the next month to have surgery on
the place where her esophagus meets her upper stomach.  She stated that
the reason for the surgery was because she had so much acid reflux that
they needed to make the hole smaller between the esophagus and the
stomach.  I was mortified.

During her first colonic she had, no exaggeration, at least 15 feet of
solid feces come out (through a one-inch tube).  That is not counting
what she had in the toilet halfway through the procedure and after the
procedure.  Much of the matter was very hard and in balls, and sounded
like stones as it bounced down the tubes.  I don't know what was
"clinging" to her colon walls and what wasn't but it was a large
accumulation of poop.

Since her colonics have begun, and since changing her diet at my strong
suggestions, she has canceled her surgery, is having more regular bowel
movements, is sleeping better, and has reduced several medications.