The honeymoon has clearly ended for Matria Healthcare ( MATR). Just months after its celebrated marriage to a competitor, Matria has crushed its fans with a disappointing outlook for the future. Notably, the disease-management firm has already lost out on one major contract it was counting on. Matria managed to hit first-quarter target, but issued new guidance that has left investors worried about the rest of the year. The company is now forecasting far less growth in the second quarter than the market had been anticipating. It is then counting on major second-half improvements to lift its performance for the entire year. Some clearly have their doubts. "It's just clear as a bell to me that the stock market doesn't believe" the full-year guidance, one investor said during a conference call on Friday morning. "Can you give us something here to hang on to? This is painful." The stock, indeed, suffered a major fall. The shares -- which peaked at $45 just two months ago -- plunged 14% to a nine-month low of $30.30 on Friday.