Perhaps your wife is taking it personally... if she is the one doing the cooking (more traditional gender roles...!) then she might feel your decision to not eat AT ALL on the cleanse , coupled with the fact you get gastro distress when you do eat, is somehow a statement about her cooking.
people are not always logical and often take things personally that are not personal.
just a thought. maybe you can reassure her somehow that it has nothing to do with her cooking/ability to care for her family... unless, of course, it does...