Posted 3/7/2018 4:50 PM (GMT 0)
I think older studies suggested mesalazine (which Pentasa is) was more effective for Crohn's than more recent studies have shown it to be. Also, there was/is an assumption that if mesalazine worked for UC, then it should work for Crohn's too - but iPoop's post explains why that assumption is wrong.
However I think the main reason why docs still use Pentasa for Crohn's is that there nothing else out there for mild Crohn's and perhaps it may help. In about 30% of cases with Crohn's the disease will continue on a mild pathway, and going on a biologic would be overkill for that subset of patients. The problem is knowing in advance which mild cases will go on to get worse and which won't - if we knew that, we could target the mild-to-severe cases in advance with stronger meds, but we don't.