Janet, one of the things I found out when I first started going through this, is that for some peoplle with IBS-C fiber theripies can actually exaserbate the C... because prior to going to the ER the first time, I was taking stool sofeners, Metamucle, and I drink about the same about of water as you are... I always have a cup, or bottle right next to me... even the Er dr was telling me to "take more fiber, get that GI tract greased up"... well for me the fiber was absorbing the water, and cauing the problem.. they started me on the Glycolax, wich is NOT fiber, its "polyethylene Glycol" powder for oral solution... it is proven to NOT ferment in the GI tract like "fiber" does, it moves through the GI tract hydrating solid waist...and is NOT absorbed by the body, tests show that it is voided in its entirey through the colon.... Just seems that the fiber your talking isn't working very well.... maybe you should ask about givig this a try...Good luck with the CT, Cat