Need Help With a MC Skeptic

Okay, so I am a Master-Cleanse fan, do it once or twice a year and love the way it makes me feel. HOWEVER I never assume that it will work for everyone and believe that we should all listen to our own bodies and do what feels best as individuals.

Recently my dubious, but ultimately open-minded boyfriend did the Master-Cleanse with me for 10 days. I was impressed! He's had chronic sinus problems his whole life that did clear up a little bit on the MC, but for the most part he felt very low energy and depressed on the cleanse (though he stuck with it without any pressure from me). Personally, I suspect he needed a longer cleanse or needs to do it again as he's probably got a fair amount of toxic build up in his 34 years without ever doing anything like this before.

But now there's trouble. We finished on Friday and he's only had one bowel movement since (and that's been negligible). His dad sent him something from the Harvard Medical School saying that the Master-Cleanse wipes out intestinal bacteria and another NYTimes article quoting a Dr. that says “Fasting for too long can deplete muscle tissue, including your heart muscle, and it can reduce the size and functioning of organs like the kidney and liver.”

Now personally I believe the masses of people who've seen the benefits of the MC first hand over a few dissenting voices from the medical community, but now my boyfriend is worried he's damaged his body and that his constipation is proof.

Can anyone help me put his mind at ease? Any studies done on the MC debunking these claims?

Thanks for the support!