I have had diahrrea for the past 3 days now with extreme gut wrenching pain. on day 2 i started passing blood. now only blood. what should i do?

OMG, get to ER now: You haven't shared your age, but what you describe sounds like such dire entities as mesenteric/gut ischemia be considered and ruled out. Please don't further delay care!

Go to ER now!: Anytime one has extreme pain, followed by new onset of bleeding, it needs to be evaluated immediately. I would call 911. Don't try to drive yourself to the emergency room. This needs to be handled immediately. Do not wait. Good luck.

You need to: seek immediate medical evaluation. A "hands on" exam is required and considering this is the beginning of a weekend a ER is most likely your best choice! Do it NOW! Hope this helps you !