Allergan's (UNKNOWN:AGN.DL) rejection of Valeant's (NYSE:BHC) newest acquisition offer has set off more speculation about the proposed transaction, with both sides ratcheting up their rhetoric. Valeant noted that the firm has "no choice but to take our offer directly to shareholders," indicating that the bid may go fully hostile, while Allergan's CEO David Pyott suggested that "The only part [of the bid] we do know how to value is the U.S. dollar portion." This highlights Allergan's general concern with Valeant's business model and claims that the company's operations are unsustainable.

In this video, from Market Checkup, the Motley Fool's health care-focused investing show, health care analysts Michael Douglass and David Williamson walk through the arguments and the next steps investors should be watching for.