diaharea & cancer

I am male, 43. For the past week I have very severe diaharea. In my family there is a history of colon cancer, so I am afraid this could be a cause for my diarrhea.

Drink lots of fluid, in order not to dehydrate, because lots of liquid is passing through you.
Diarrhea is a sign of many diseases, so it very hard to say if you have a colon cancer... hope not. But, if you have a case in your family, you have greater exposure to it.
You should really go to see a doctor to be more secure... besides, if you have diarrhea more than a week, you should anyhow go see your doctor.
Best wishes!