Hello, I'm new to this too. And Crohn's came as a surprise for me as well.
Do you have a follow-up appointment with your doctor? If not, I would suggest you do this. I also suggest you get a second opinion from a different GI regarding your treatment options. If you have choices in doctors, consider finding a new one...living with Crohn's you need a GI you like/trust/someone who returns your calls.
1. A few things I would ask:
(a) How will your progress be monitored, as you can't have scopes all the time and you don't have consistent symptoms? You can monitor you white blood count, ESR or C-Reactive Protein via blood tests if they are currently elevated.
(b) How he plans to treat you short and long term. And why those meds were chosen. Since you seem to have a mild case, I think you ought to be able to try Entocort instead of Prednisone. I thought Pentasa, not Asacol, was usually used for ileal disease?
(c) If this has not been done already... politely ask "Should I be tested for anemia/B-12/folate/Iron..." Several things that tend to be low if you have Crohn's.
2. Those meds will knock down the body's inflammatory process but don't necessarily bring about healing. Going on enteral nutrition (liquid diet) can help healing. I am guessing things like antibiotics or stronger drugs like remicade could since they can help to heal fistulas.
3. Meds will do nothing for scar tissue. At this point do you know if your narrowing is inflammatory or scar tissue? If it is scar tissue the only thing you can really do is chew well and avoid things like fruit skin, nuts, popcorn, etc. that might block you up.
4. That's up to you, but your doctor needs to be comfortable with what you're doing. I am in a similar situation: I have narrowing and ulcers at the terminal ileum, no change in bowel habits, but I did get fevers. My GI suggested Entocort and Imuran, but gave "doing nothing" as an option. I chose to avoid meds for now as I am just coming of a separate drug-related liver injury. I am on a 100% liquid diet, similar to Ensure, and barring no change in how I feel that's all I'm doing. My GI was OK with it and asked for frequent blood tests and a follow-up in three months.
I certainly suggest that you do something. In addition to meds, there are other things that could help: mild exercise, supplementary Omega-3 fatty acids, Vitamin E, probiotics, etc., and there are certain diets (Maker's, Specific Carbohydrate Diet) that people have had success with.
5. That's a question to ask your doctor. In general, yes, doctors use that to maintain remission...however, only for mild cases, and whether 5-ASA drugs actually do that is controversial (there is only good evidence for the immunomodulators Imuran and 6-MP, and anti-TNFs). My impression is people stay on Asacol indefinitely until they have another flare and move on to more powerful drugs.
6. I assume he wants to start the meds now because things did not get better. Having inflammation is not a good thing, even if it doesn't bother you. The chronic inflammation will create scar tissue, leading to strictures, for which the only option is surgery. Having active Crohn's in the ileum also can cause malabsorbtion.
7. I don't think there is a set guideline on this. Regarding the he risk for colon cancer, it is not as elevated in ileal Crohn's as it is for UC or Crohn's colitis. I had my first in December. Like you, the only way for my doctor to "really" know what's going on is by a scope. But he did not want another one until after a year, and after that, I don't know how often.