The U.S. Centers for Disease Control and Prevention defines chronic diarrhea as diarrhea that lasts for more than two weeks. When it's persistent, it may be a sign of a serious medical illness or condition requiring immediate attention. These illnesses or conditions may prove life-threatening for people with weak immune systems.
Infections From Bacteria or Parasites
As Jackson Siegelbaum Gastroenterology explains, more than 400 different types of beneficial bacteria live in the large intestines. But other types of bacteria and parasites exist that cause infections resulting in chronic diarrhea. Some of these include salmonella, shigella, Escherichia coli, giardia lamblia and entamoeba. Some bacteria--such as salmonella--enter the body via food, while certain parasites such as giardia contaminate streams and well water.
Celiac Disease
Celiac disease is a digestive disorder affecting children and adults--one that lasts a lifetime, according to the Celiac Disease Foundation. It can develop at any time for various reasons including surgery, viral infection and stress. People with Celiac disease have an intolerance to foods with gluten, a protein found in certain grains. When eaten in even the smallest amounts, it can damage the small intestine and doesn't allow proper digestion of food. Other symptoms include unexplained anemia, weight loss or gain; behavioral changes; recurring bloating, gas or abdominal pain; missed menstrual cycles and tooth discoloration.
Prescription Medications
The Mayo Clinic says a number of medications can cause chronic diarrhea, namely as a side effect. Jackson Siegelbaum Gastroenterology warns that if you have a noticeable change in bowel habits occurring after starting a new drug, report it to the prescribing physician. Antibiotics are one of the most common drugs responsible for chronic diarrhea. Their job is to destroy bad bacteria, but they also destroy the good bacteria. This interferes with the sensitive balance of bacteria in the intestines and can sometimes lead to an infection with bacteria known as Clostridium difficile. This infection can also cause chronic diarrhea.
Irritable Bowel Syndrome
The National Digestive Diseases Information Clearinghouse says irritable bowel syndrome is one of the most common disorders doctors diagnose, affecting as many as 20 percent of the adult population in the United States. Although the exact cause is not yet known, one theory is that those who suffer from this disorder have a colon or large intestine that's over-sensitive to stress and certain foods. This condition causes its sufferers great discomfort but does no permanent damage to the intestines. For some, it can interfere with their daily lives to the point of being disabling. Other symptoms include abdominal pain, bloating and cramping.
