When most people think of Warren Buffett's investment philosophy they think of his large positions in iconic companies such as Coca Cola, Burlington Northern, Geico, Wells Fargo, etc. These investments are core positions where he was able to allocate huge sums of money with the understanding that the franchise values would continue to grow over time. These types of businesses aren't easy to buy at great prices so when he had the opportunity he bet big.
Before Berkshire Hathaway reached such a massive size Buffett engaged in a great deal of merger arbitrage investment which he termed as "workouts." Distressed debt investing is a type of "workout" because the bonds will either pay off at par, or they will likely be converted into a combination of cash and equity through the bankruptcy process. Buffett still executes these types of investments when he is allocating the massive float from his insurance operations, but because many of them aren't large enough to necessitate public disclosure we don't hear much about them. At T&T Capital Management we attempt to emulate many of Buffett's strategies particularly those that he employed when he was running the Buffett Partnership L.P. prior to his acquisition of Berkshire Hathaway. This WSJ piece describes Buffett taking advantage of pressured selling on a small quantity of bonds from Goldman Sachs and I think it is a fun and different perspective into Buffett's methods.