Can too much tea (or coffee) aggravate the colon and rectum to where it bleeds?

It's Wpossible: But not likely. The caffeine in tea and coffe often stimulates the bowel, but rarely causes enough irritation to cause bleeding. Watch stools for further bleeding, if persistent, need to see health care provider.

Caffeine: Hello, too much of anything isn't always a good thing. It (caffeine) would probably have little to do with the bleeding you are describing. See your doctor.