On the opposite end of the spectrum, diarrhea can also be a sign of colon cancer. If you have been experiencing persistent diarrhea for more that a few weeks, it could be an early symptom of colon cancer.
If a tumor is partially obstructing the bowel, it may cause constipation alternating with diarrhea as stool leaks out of the rectum.
If you have diarrhea that lasts for more than 2 weeks or if you have alternating diarrhea and constipation, it is a good idea to consult your physician. Persistent diarrhea can lead to dehydration as well as drain your body of important nutrients. It may also be a sign of another serious problem such as colon cancer.