Hi and welcome!
I've been on 16 Asacol a day for 8 or 9 years - and wow, I'm sure glad to have company! lol
I used to not think Rowasa helped me..... and I'm not sure, maybe I was just not patient enough. But for the past year, the least I've done is 2 Rowasa a week, and the most.... well, when I was heading into a flare last summer, I was doing 2 a day. They did not head off my flare, and cortenemas did, within 48 hours. I also increased my VSL.)
I basically don't worry about
decreasing my oral meds. At some point if I'm in a soild remission for at least a few months I may try to decrease to 12 (gradually)... but when I tried that in Fall I had symptoms restart.
My GI says it's hard to OD on 5-ASAs..... and I believe him. (I know there are exceptions, folks who are highly sensitive, etc.....)
I guess if I were you and wanted to decrease, I'd add more probiotics and then decrease one of the enemas, say, the morning one, by every other day for.... like 2 weeks at least, see how that goes.... and do it really gradually. Or try a Canasa on those days instead.
Keep us posted, and again, welcome, fellow "16er" !