Confirm it? Hardly. There’s one 26-year-old journal article that none of us but Cecil has apparently read. And Cecil himself says it’s a “minority view.”
I know I’m on unsteady ground debating medicine with an MD, but I still say I’m not convinced, and I certainly can’t let such a gross misrepresentation of The Master’s words go unchallenged.
Now, that said, I agree with the conclusion even if I challenge the logic behind it. Let It Out! My reasoning is: it makes you feel better.
Here’s a few sites. Granted, not a lot of hard evidence that retained flatus alone causes tics, but definite evidence that reduction in transient colonic pressures reduces formation of tics (generally in the form of adding fiber, so less straining at stool). And evidence that elevated intra-intestinal pressure in the elderly can lead to diverticulae rupture. Also some nice charts showing how high gas pressures can go! Also clinical findings that passing flatus transiently reduces the pains associated with diverticulitis. Have fun!
http://cpmcnet.columbia.edu/texts/guide/hmg22_0006.html
http://www.med-help.com/Diverticulitis.html
http://www.attgi.com/div.html
http://www.pharmweb.net/pwmirror/pwz/conditions/gastin.html
http://www.mcare.org/healthtips/homecare/DIVERTIC.HTM
http://www.gihealth.com/TREC2/articles/diverticulosis.html
http://healthlink.mcw.edu/article/930605239.html
http://webmd.lycos.com/content/dmk/dmk_article_1452682
OK. That’s an impressive number of links. But none of them really say that “holding farts causes diverticulitis.” Many say that increased intestinal pressure aggravates it, but as for the cause, none of them blame anything other than a long history of diets poor in fiber.
The questions that need to be investigated next are “How much extra pressure over what kind of surface area does withheld flatus create, as compared to expelled flatus?” and “Do diverticuli form as a result of transient pressures associeated with episodes of flatulence or from long-term intestinal pressures associated with chronic constipation?”
I’ll concede, with a statement that it’s likely that “holding farts” is a contributing factor, but it remains to be proven.
Excuse me while I go have a bran muffin and a glass of metamucil. 
Excuse me, Dr., but I would think that the opposite sequence of events would be more pleasing to the hidden child inside all of us - let fly and THEN leave the room.
Well, since my original statement was:
“Failing to vent flatus may be a contributing factor to diverticulosis”, I think that’s fair!
that was fun! Let’s do it again sometime!