Minerals are best gotten from vegetables and whole grains in order to be balanced and absorbable, but if you've been anorexic an actual mineral type vitamin complex might be a good idea for a short time, just a small bottle. :) Solary has a mix that focuses on minerals. Celery is an excellent source of organic salt. Parsley, cilantro, kale, spinach, will provide you with tons of minerals. :) Super green is great for that too.
When I do enemas I lie on the floor on my back, so it's no problem to rest my feet on a roller - or golf balls. :) That way I can lift my buttocks off the ground and let gravity help the water up the descending colon. Works out great! :)