You're saying you know multiple people who get cramps and stomach ache every morning and are certain its from weed withdrawl? I've never heard of any study that found any physical withdrawl symptoms from marijuana other then some restlessness and perhaps trouble sleeping, and I've seen quite a few studies on the subject. Marijuana is very minimally physically addictive if at all.

If I started getting daily morning withdrawl symptoms from any substance I was using, I would stop using it... be it herb or whatever. Addiction isn't a good thing... just my opinion. Luckily herb doesn't have that effect on me. Then again I don't smoke much, usually just a few hits once a week or so at the most.