Changes in bowel habits, such as narrow or pencil-thin stools, can also indicate a possible obstruction in the colon. When a tumor narrows the intestinal passage, stool can change in shape and consistency. Recurrent constipation, diarrhea, or alternating between both are additional warning signs that the colon’s normal function has been disrupted. Health experts recommend that if such symptoms last for more than a week, individuals should undergo a professional examination, including possible colonoscopy.
