The nurse has attended a continuing education conference regarding irritable bowel syndrome (IBS). Which of the following statements, if made by the nurse, indicates a need for further teaching?

a. "IBS has no identifiable pathological process associated with the dysfunction."
b. "Myoelectric activity of the colon is altered, resulting in hypoactivity of peristaltic action."
c. "The etiology of IBS is not fully understood or known."
d. "Clients can have either constipation or diarrhea, or a combination of both."