Yes go ahead an continue, but you need to decrease the amount of omnacortil slowly (decrease it by 5- 10mg per week) until 6-8 weeks have passed by, then stop. At the same time you should be taking mesacol OD, without decreasing the dose. You should continue on Mesacol OD until further notice. If Mesacol OD itself does not control your symptoms then you need to be on a stronger medication such as azathioprine (pill) or infliximab (intravenous), or both. Try to avoid more treatment with omnacortil in the future, since it is a steroid, and has many many side effects (it can cause high blood pressure, diabetes, weaken your bones, increase your weight, change your mood, etc).