Diarrhea, a condition characterized by frequent, loose, watery stools, allows the body to rid itself of toxins and foreign substances. In a normal digestive system, food remains in liquid form until it reaches the colon, where the body absorbs most of the liquid, leaving behind a semi-solid stool.
When you have diarrhea, however, the liquid moves too quickly through the colon. The body's need to rid itself of toxins quickly or inflammation of the colon lining may cause this reaction. According to the University of Maryland Medical Center, diarrhea occurs in two forms -- acute or chronic. Acute diarrhea, typically related to viruses or bacteria, clears up within a few days, while chronic diarrhea may last longer due to a disease or functional disorder.
Viruses
Viral diarrhea spreads easily among people, as highly contagious viruses quickly infect the body upon exposure. Common viruses that cause diarrhea include cytomegalovirus, the Norwalk virus, herpes simplex and viral hepatitis. The rotavirus causes the most severe cases of diarrhea in children and infants, though a recently developed vaccine may protect against it. According to the National Digestive Diseases Information Clearinghouse, viral gastroenteritis, caused by the rotavirus, adenovirus, caliciviruses and astrovirus, result in millions of cases of diarrhea each year.
Bacteria and Parasites
Other common causes of diarrhea include bacteria and parasites, both of which can contaminate food and water or spread through contact with other people. Parasites that cause diarrhea by settling into the digestive system include Giardia lamblia, cryptosporidium and Entamoeba histolytica. Common bacterial infections that result in diarrhea include salmonella, shigella, E. coli and campylobacter, which usually spread through contaminated food. Bacterial and parasitic diarrhea, also known as traveler's diarrhea, frequently occurs in developing countries.
Medications
In some cases, prescription medications may cause diarrhea. Antibiotics, the most common culprits, destroy both good and bad bacteria in the intestines. This upsets the natural bacterial balance in the digestive tract. Sometimes, this disturbance causes a bacterial infection known as Clostridium difficile, which also causes diarrhea. Other medications that may cause diarrhea include blood pressure medications, antacids containing magnesium and drugs prescribed for the treatment of cancer.
Other Causes
Other less common causes of diarrhea include intestinal diseases such as inflammatory bowel disease or ulcerative colitis, bowel disorders such as irritable bowel syndrome, overuse of laxatives, abuse of alcohol or drugs, cystic fibrosis, pancreatitis and recent surgery of the stomach or gallbladder. In some cases, food intolerance or allergy may cause diarrhea including lactose and fructose intolerance or intolerance to artificial sweeteners.
References
- Mayo Clinic: Diarrhea Causes
- National Digestive Diseases Information Clearinghouse: Viral Gastroenteritis
- University of Maryland Medical Center Digestive Disorders: Diarrhea
- Intellihealth: Diarrhea, Acute (New Onset Diarrhea)
- "Smart Medicine for Healthier Living"; Janet Zand, Allan N. Spreen, James B. LaValle; 1999
