When did you start Remicade?
Have you had the blood tests for your infliximab trough levels and to check for antibodies to infliximab (ATIs)?
Also, 50 mg of imuran is pretty low. Generally speaking, dosing is 2.5mg/kg, which works out to just a little over your weight in pounds.
Advice is to do the scope and check your levels as above. Then let us know!