So I am 3 weeks post sleeve. I'm allowed to go to full liquids I had butternut squash soup at dinner. After about 5 small spoonfuls I got a horrible pain in my side. Then when I stood up I almost passed out. Has this happened to anyone when changing stages.

I never had any pains. Try a different kind of soup. Your stomach may just not like that kind of soup. If it still happens, continue with clear liquids until your stomach is ready.

I haven't experienced pain like that. I agree with Z28 that you should try a different soup, but a follow up call to your doctor isn't a bad idea. They'll ask you questions and bring you in if they think there's a problem.