Oils good for the base or sacral chakra would include Vetivert, Cedarwood, Sandalwood, Patchouli and Cedarwood. Jasmine is more a 2nd chakra or Creative/Sexual chakra oil.
As for the intestinal pain, if you have not had it checked out you may want to think about it. It could be as easy as bad digestion, or a food allergy, but it could also be a sign of something serious.
Aromatherapy and Truly Natural Body Care