Diarrhea is defined as loose, watery, and frequent stools. Food poisoning and traveler's diarrhea are two other common causes of diarrhea. They occur from eating food or drinking water contaminated with organisms like bacteria and parasites.

SIGNS
Joint pain or muscle pain, swelling, joint stiffness, discoloration of the skin, especially bruising.

FIRST AID
Drink plenty of fluid to avoid becoming dehydrated. Start with sips of water or any fluid other than milk or caffeinated beverages. For infants and young children, use electrolyte solutions like Pedialyte.
Avoid solid food for about 24 hours, until your symptoms begin to subside. Stick with clear liquids during this time, like clear soups and jello.
When you resume eating, start with mild foods like rice, dry toast, and bananas. Avoid dairy, fruits, vegetables, alcohol, caffeine, and spicy foods until your symptoms have been gone for a couple of days.
Avoid over-the-counter diarrhea medications unless specifically instructed to use one by your doctor. Certain infections can be made worse by these drugs. When you have diarrhea, your body is trying to get rid of whatever food, virus, or other bug is causing it.
Rest.

SEEK CARE IF:
You have blood or pus in your stools or if your stool is black.
You have abdominal pain that is not relieved by a bowel movement.
You have symptoms of dehydration.
You have a fever above 101 degrees Fahrenheit or your child has a fever above 100.4 degrees Fahrenheit along with diarrhea.
You have foul smelling or oily-looking stools.
You have recently traveled to a foreign country.
Other people that you have eaten with also have diarrhea.
You have started on a new medication.
Your diarrhea does not get better in 5 days (2 days for an infant or child) or worsens before that.
Your child has been vomiting for more than 12 hours. In a newborn (under 3 months), you should call as soon as vomiting or diarrhea begins.