Final answer:
Patients who have bright red blood in their stools may be experiencing gastrointestinal bleeding, which can be caused by various conditions. A stool sample may be ordered by a physician to identify the cause of the bleeding.
Step-by-step explanation:
Patients who have bright red blood in their stools may be experiencing gastrointestinal bleeding. This can be caused by conditions such as ulcers, hemorrhoids, gastritis, or certain types of cancers in the gastrointestinal tract. It can also be a result of excessive use of nonsteroidal anti-inflammatory drugs or excessive menstruation. To determine the cause, a physician may order a stool sample to identify possible causative agents and look for the presence of blood.