I do have a canister of unsweetened cocoa powder in my house, and it contains just that: cocoa powder. No lactose, no sugar. I think the reason chocolate isn't allowed is as a previous person already said, even without the sugar and other stuff often associated with chocolate, the cocoa itself has addictive tendencies for some people (though I have never especially liked chocolate, so I guess not addictive to everyone).
I had been on the SCD for several months, and then ate a dark chocolate covered almond. One (1). Someone gave it to me, it seemed like a good idea at the time, and I ate it. Pretty tasty, but not worth the 3 hours of very bloated gassiness it gave me later that day. Wow! That experience alone made me not want to eat any more chocolate.
Ulcerative Colitis diagnosed April 2010 at age 37
Female, mom of 2
Canasa made things worse. Hydrocortisone made no difference.
Tried "Specific Carbohydrate Diet" ... Jun - Nov 2010.
Currently following Weston Price Foundation dietary advice, also Gluten-free.
Trying alternative routes to healing, including Traditional Chinese Medicine