Hi there, This is Dr Basu, Experienced Specialist. I am here to address your concerns and provide great service.
Warfarin is a strong blood thinner.
This can cause bleeding from the intestine and stomach commonly.
The drop in hemoglobin over time suggests possible bleeding from his intestine or stomach.
The best way to diagnose this will be to get endoscopies done.
Warfarin should be stopped ideally if bleeding is suspected to prevent any further bleeding.
usually it indicates ulcers.
also bleeding polyps.
also bleeding blood vessls.
tumors are one possibility only.
usually not cancerous.
but sometimes, yes, colon cancer is a possibility.
See, the worrisome point is to stop the bleeding first.
His hemoglobin should not be lower than 10 to avoid any heart problem.
That is why warfarin should have been stopped while waiting for further evaluation.
He should improve soon.
Please make him follow a iron rich diet for now.
Lots of green leafy vegetables, red meat.