Wells Fargo analyst David Maris said in a research note late Friday that Valeant Pharmaceuticals views the FDA's new guidance for generic Xifaxan as a positive. Management believes the guidelines may delay generics which may not have conducted their studies to be compliant with the new guidance, Maris told investors in a research note. The analyst earlier in the day Friday told investors that he views the FDA's guidance as a "game changing development that makes it much easier for generics to show bioequivalence." Maris called the news a "new significant negative" for Valeant. He says his initial read is not changed by Valeant management's view, but added that he will review the feedback with outside consultants and other industry sources to gain a broader perspective. Maris has an Underperform rating on Valeant, his firm's equivalent of a sell. Shares of Valeant closed yesterday down 17c to $11.03.