A 50 year old woman presents with a history of chronic bloody diarrhea. She denies massive amount of blood per rectum. Physical examination of the heart reveal a murmur that starts immediately after the first heart sound, gradually rises in pitch and gradually decreases before the second heart sound. She denies shortness of breath and abdominal pain. This combination of findings is most consistent with which of the following?
a. Colon carcinoma
b. Congestive heart failure
c. Coagulation abnormality
d. Rheumatic disease
e. Ischemic colitis