Wow...that's definately a new one for me. The anti-fluoride people always say that fluoride is linked to everything from autism to brain tumors to cancer. Never heard them pull the Crohn's card before.
Fluoride especially in toothpaste (and water) is needed to keep teeth from decaying. Natural toothpaste doesn't have any and usually end up with people getting decay. Definately need the fluoride with the soft diet that most of us are on for Crohn's and dry mouth some of the meds cause. All that predisposes for caries.
Sadly, there is no alternative to fluoride...
Makes me wonder who comes up with some of these ideas...they are pretty funny though. If someone knew the cause of Crohn's, they'd make a huge difference though...maybe someday someone wil be on to something like this?