Diarrhea Health Article

Definition

Diarrhea is an increased frequency of stools or bowel movements (more than two or three per day) or liquidity of feces.

Description

In a normal adult, about 10 quarts (liters) of fluid waste leaves the stomach each day. All but a liter and a half is absorbed in the small intestine. The unabsorbed contents enter the large bowel or colon. Most of the fluid in the feces is reabsorbed by the large intestine. The fluid loss is about 100 milliliters each day. From a strictly medical perspective, diarrhea is defined as stool weight of more than 250 grams in 24 hours. In practice, the calculation of stool weights is restricted to persons with chronic diarrhea.

There are three broad classes that encompass most cases of diarrhea.

• Non-inflammatory diarrhea. This is described as a watery, non-bloody bowel movement that is associated with diffuse abdominal cramping, nausea, vomiting or bloating. The most common cause of non-inflammatory diarrhea is a bacterium that produces a toxin. Common examples of non-inflammatory bacteria include Escherichia coli, Staphylococcus aureus, Bacillus cereus and Clostridium perfringens. Some viruses and amoeba such as Giardia lamblia also cause non-inflammatory diarrhea. This diarrhea is typically mild but may be voluminous, involving large amounts of fluid (10 to 200 mL/kg/day). Such fluid loss results in dehydration and loss of electrolytes. There is usually no blood loss.
• Inflammatory diarrhea. This is usually characterized by the presence of fever and blood in the stool and is associated with left lower quadrant cramps, urgency and tenesmus (anal spasms). Common causes of inflammatory diarrhea include infection with Campylobacter or Yersinia species or infection with some species of Escherichia coli. Diarrhea due to these pathogens tends to be less voluminous, less than 1 liter per day.
• Enteric fever. This is characterized by abdominal tenderness, confusion, prolonged high fever, prostration and occasionally a rash. Common causes of enteric fever-related diarrhea include Salmonella typhi or Salmonella paratyphi. Multi-organ disease is frequently encountered.

Inflammatory diarrhea must be distinguished from ulcerative colitis.

Non-professionals may use the term diarrhea in reference to increased incidence of bowel movements, a sense of fecal urgency, increased stool liquidity or fecal incontinence.