Well, yeah, it might not be anything related to something a blood test would reveal. Docs are looking for a disease state, which you may have, but you might not have one. It could be the way you're eating. It could be you're not moving enough. It could be lack of fiber. Could be lack of water. Could be you just don't have to go, and you're forcing it, as you say it's off and on. Could be emotional. So it is possible it's not something a blood test will show. That's why the docs are moving on to other kinds of tests. But you might also not have a disease in that sense, so you might if they don't find anything look to what might have happened or changed 4 weeks ago.