Diarrhea can be defined as a condition of stool looseness or as a increased bowel movements frequency.
It also can be a result from the both.

Sometimes diarrhea requires medical help

If the digestion is normal, stomach, upper small intestine, pancreas, and gallbladder keep the food liquid, because they secret a large amount of water. Food that is not digested goes to the colon and the lower small intestine as liquid. Then, by absorbing the water, colon and the lower small intestine turn undigested food into a stool.

The amounts of water in the stool may increase if the stomach secrets too much fluid, if the food that is not digested passes too quickly through the small intestine and colon or if the colon and the distal small intestine can’t absorb enough water. Each of these unusual conditions can cause diarrhea. They can even occur at the same time.

Diarrhea is generally divided into absolute and relative terms, according to the looseness of stools and the frequency of bowel movements. For instance, when diarrhea is absolute, there are more bowel movements than usual. The normal number of bowel movements of healthy person is 3 and anything above that can be problematic.

Sometimes visitation to doctor is required. If you experience some of the following symptoms: abdominal pain, high fever, severe dehydration, bloody diarrhea or one that tortures you more than 48 hours, it is good for you to see a specialist.