The Infamous Stool Sample

Toward the end of a very rough day in the office, one of my patients tells me, "Doc, I have just one more complaint. . . ."  When a patient phrases it like that I have learned to brace myself, 'cause it's usually chest pain, or something major they saved for the last minute. Today, however, this patient says, "I brought you a stool sample thinking you were going to need it."  

Now, when a patient brings you a stool sample and reaches into their pocket to pull it out, you really begin to worry. He tells me he has been having trouble with his stools and thought he would bring me this sample to examine.  He wanted a diagnosis right there on the spot. . . 

So, I ask you, what's your diagnosis?