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.
Dx Crohn's in June 2000. (Yay )
Tried: 5-ASAs, azathioprine, 6MP, Remicade, methotrexate, Humira, diets.
1st surgery 20/2/13 - subtotal colectomy with end ileostomy.
2nd surgery 10/7/15 - ileorectal anastomosis. Stoma reversed and ileum connected to the rectum.
Current status: Chronic flare. Do I have any other kind?
Current meds: 50mg 6MP; Entyvio (started 3/11/16)