If the urine, vomitus, or stool exhibit color changes while taking heparin, the patient must notify his or her health-care provider because there may be:

A) an embolus
B) an allergic reaction
C) internal bleeding
D) an infection

C) internal bleeding
Patients taking heparin must notify their health-care providers if their urine is pink, red, dark brown, or cloudy; if their vomitus is red or dark brown; or if their stool is red or black. All these color changes may be signs of internal bleeding.