they also have flexible sigmoid colon checks..that are done while you're awake, they go up with a flexible tube much like a colonoscopy but only go a short distance.
or what I think they call "digital exams" (finger and glove) but yeah you should get checked for it. Probably short term hit the Fiber and see if you improve.
You may want to check this out with your doctor. When grooves or other patterns are found in the stool day after day, it may indicate changes are occurring within the colon. You may want to think about discussing having a colonoscopy done with your doc just to make sure nothing is amiss.