Alcohol is an anti-nutrient, interfering with the absorption of, for instance, B vitamins. Seems many Crohnies, already suffering from malabsorption issues, don't need more problems with absorption.
I'm sorry, but I have to say this doc really seems like an idiot, offering no solid evidence whatsoever. The last thing we need is a bogus claim about alcohol.
While it's true that a glass of red wine offers some benefits, the same benefits come from eating grapes or drinking grape juice...this way, you skip the antinutrient issues and get to keep more brain cells.
The above said, the SCD diet does allow certain types of alcohol in moderation. That means a glass, not a binge.