Q: I always thought that in order to say you've officially run a marathon, it wouldn’t be true if you had to stop and walk. It sort feels like cheating. How do you get over that stigma that you have to run the entire thing?
Jeff: One of the wonderful aspects of running and marathoning is that there are no rules about how much to run and how much to walk.  The goal is to finish-any way you can.  My run-walk-runTM method has allowed beginners to achieve this accomplishment.  Runners of all abilities have been able to enjoy the experience with run-walk-runTM.  Time goal runners tend to run an average of 13 minutes faster when they use the right ratio of walking.
Walking has been used from the beginning of our sport.  A few years ago, in a museum in Athens, Greece, I found a first hand newspaper account of the first marathon race: the Olympic Marathon in 1896.  According to the author, who went along with the runners, every one of the athletes walked significantly.  I'll bet they told their friends that they officially ran the marathon.
You are authorized to walk as you wish, and you will receive the medal that designates that you are a real marathoner.
I wish you the best in your journey.