There has been a lot of evidence posted about psyllium and its damaging effects on the intestinal tract, among other potential detrimental effects. Snozberry posted a (moderator recommended) message about it on this forum approximately 2 months ago.
Also if you read through information on the barefoot herbalist site he has come to similar conclusions.
As far as the Candida that has 'drilled into the intestinal tract'. Candida is the bodies natural defense against over-toxicity, and will remain in check once the toxic waste is largely removed, and the organs (particularily the liver) and stomach have gone through significant healing. I cured a 4 year battle with candiasis. Id suggest using slippery elm, it gently pulls out waste while re-building the intestinal wall, healing any damage caused by the Candida.