Welcome to the right place to get information from peers. All of the information received is helpful and there is still so much you do not know but will learn, sadly we all do.
The one thing I haven't seen mentioned, and if it has been I am sorry to repeat, one of the most important factors in your treatment may be surgery. If so, the services of a board certified colorectal surgeon are imperative.
The sigmoid area is low, and there are no guarantees as to needing a diversion (ostomy) either temporary or permanent, but the most skilled general surgeon is not up to the speed that a colorectal specialist is.
Keep coming back as you will learn more each time, and when you have your full test results, the experienced members here can give you more information on their own experience.
What has been said already is true, with the same disease we are all different, so you can cull the information that pertains to you for getting your questions together whenever you see your docs.
Best wishes as you begin the journey.