ML is a 19 year old student who walks into clinic seeking a product recommendation for constipation. Her last bowel movement was two days ago. She was diagnosed with anemia one week ago; she has started taking ferrous fumarate 300 mg po BID. Ever since she started iron therapy, her appetite decreased and ML finds it difficult to have even two meals a day. ML drinks 6 glasses of fluids daily. She gets little exercise but is not obese. She admits that she does ignore the urge to defecate。 All of the following are risk factors for ML's constipation, EXCEPT: