I think it is possible.
I used Rowasa on my daughter last weekend for the 1st time and I only used maybe 1/4-1/2 of the bottle.
i did it at 7:00pm and by 12;30am she was up with bloody D and continued to do worse over the weekend.
I am finally pulling her out of this by using Cortenemas 2 times a day and loads of probiotics.
She did not tolerate oral mesalamines and clearly using them from the other end doesn't work either.
Maybe you will be fine and you will never know what happened but things can and do change.
Good luck to you