There are two schools of thought about medication protocols. Top down and bottom up.
Top down - Start with the strongest medicine and knock the Crohn's into remission ASAP, then move down to other drugs to maintain remission.
Bottom up - Start on the mildest drug and keep moving up in strength until remission is acheived. This method wants to avoid the strongest drugs as long as possible since Crohn's is a lifelong illness and doctors don't want you to be out of medication options early in the disease if they can avoid it.
Which method your doctors go with will depend on your country, your doctor's preference, the stage of your disease, the agressiveness of your disease and your personal feeling on taking medications.
Some of the drugs used to treat Crohn's inlcude:
Pentasa, antibiotics,steroids, imuran, 6MP, Humira, Remicade
This is not a complete list with Pentasa being one of the milder options and Remicade is one of the strongest as it is an immunosupressant.
This forum is a great source of information and support, so I hope you hang around. Hope the next few weeks go well and you are not suffereing too much.