to the op, try lowering the amount of salt in the water to just a tiny pinch per glass if that.
1/2 teaspoon may be too much and will cause a cleansing reaction which will cause you distress.
salt water purges are an ayurvedic cleansing method for the intestines and will stir up all sorts of things including fungus, parasites, bacteria, intestinal plaque. usually novices who undertake this type of cleansing are assisted by an experienced vaidya.
i think your cramping is cleansing reaction, but you don't want to do this every day of your life. if it is in the lower left side of your abdomen it is most likely worms.
there is a balance you want to achieve while cleansing, and especially with adrenal issues you don't want to push yourself too far out of balance unless the gains you make will be permanent afterwards.