Assuming you do not have IBS or any other type of intestinal disorder. When you wake up in the morning, and get out of bed, the various organs, or muscles of your body may not function at 100% efficiency for a period of time from several minutes to several hours to fully wake up. Some people, most people have to urinate after they wake up and some do a BM because that is their normal rythm. ( did I spell rythm correctly) You may have feces in your lower colon that are ready to be expelled from the body. There may also be feces in the upper part of the colon that haven't worked their way down as you slept. As you move about, your muscles come awake and push the feces into that part of your colon that triggers a muscle response. I experience something similar myself periodically and know a few people who also go through the same thing, though I have some GI issues.... The question you need to ask yourself is: When you go potty later in the day and have a BM, does the same thing happen again? If it does, it might be a good idea to get yourself checked out by a doctor because it might( not is, but might) be indicative of an intestinal or colonic issue.

Your full of shit!lol