Hi Brinycbri,
You ask a good question. Everybody is different, and there are no absolutes. For the most part, I generally have NO outward symptoms of Crohn's---hardly ever have diarrhea (usually have constipation, instead); and only have occasional cramping which may occur when I eat something with a lot of fiber. When I go to the gastro and he presses on my lower abdominal area, I feel some tenderness---but on a daily basis it's generally not something I notice.
As for surgery, I've been fortunate so far to not need it. The stats say that there is a high percentage that a person with Crohn's will need a surgery or two SOMETIME in their life. But once again, there are no absolutes.
It also seems (& even according to research) that there may be several different TYPES of Crohn's; some of which may be more aggressive and symptomatic than others.
Even though I don't generally have OUTWARD symptoms, I do have the characteristic inward signs of Crohn's---Stricturing (narrowing) and inflammation (and probably some ulcerations) of the terminal ileum. Just keep in mind that it's not the outward symptoms that do the damage; it's what's going on internally. Therefore, I still need to be on medications to hopefully shove this into remission to delay the progression of the disease, at least temporarily.
So PLEASE don't lose hope, and understand that everyone is different. Typically when you read information on the Internet about Crohn's, it discusses the "typical" and sometimes worst case scenarios. The articles simply generalize.
I wish you the best of luck, and hope that you're one of the fortunate ones to be in the category of a less aggressive type.