You can make an ORS with plain water, baking soda, sugar, KCl (sold as salt substitute) -- see the WHO recipe on this page:
www.oley.org/lifeline/ORS.html.
I'm a big plain water drinker too and honestly it's easier for me to drink dilute Gatorade or something like that than the water based ORS -- adding enough stuff to make it hydrating makes it taste like "contaminated water" to me so I suck it up and usually do diluted Gatorade with a bit of salt.
As time goes on you will probably be able to switch back to plain water. With my loop I took 6 Imodium per day but drank plain water and iced tea -- I needed to take Imodium no matter what and I preferred to take an extra tablet or two rather than not be able to drink plain water.