Moo, allodwick, I rather suspect we're getting caught up in a false dichotomy of INR v/s gastrointestinal bleeding.
I've read in a number of places that alcohol interacts with Warfarin to produce a higher INR.
I've also read in a number of places - places completely unrelated to Warfarin - that drinking increases risk of gastrointestinal bleeding.
Back to the ongoing theme of how group statistics (upon which all studies other than single-subject case studies are based) don't apply to individuals (otherwise we'd all have IQ's of 100)...
Looks like there's at least one person whose INR isn't affected by alcohol, wouldn't surprise me if there were many many more. I hadn't known that until Moo's selfless experiment in the name of Science, although with the rule of group statistics not applying to individuals I should have been able to figure it out. Note that we had a thread here about a lady who went over 20 years with an artifician valve with no Coumadin/Warfarin on board and she apparantly did OK - and that does not mean that it's then quite safe to discontinue your Coumadin/Warfarin if you've got an artificial valve.
And that Moo drinks does not necessarily mean he'll get gastrointestinal bleeding - just that he's at greater risk than if he didn't. I used to do alcohol and drug counseling, and can attest that gastrointestinal bleeding is pretty common among heavy drinkers. But not every heavy drinker gets it, and I would not agree with allodwick apparant statement that it's inevitable. I have no experience to draw upon with regard to gastrointestinal bleeding among light-to-moderate drinkers.
And finally, Moo, I wouldn't necessarily read allodwick's posts to mean that alcohol has no effect on INR's, just that the effect on INR's isn't as dangerous as the potential for gastrointestinal bleeding.
Alcohol is just one of any number of places where one has to make a decision in the trade-off of costs versus benefits in determining what, if any, diet and lifestyle changes one makes after being put on Coumadin/Warfarin. For example, I gave up motorcycle riding. If that was very important to me, I wouldn't have given it up but instead would have taken on the increased risk of bleeding from road-rash that motorcyclists take on. I've also given up power drinking, but my drink of choice (straight bourbon) is one that's probably much more likely to cause gastrointestinal irritation than Moo's beer.