Shauna is a healthy, fit 28-year-old who decided to go on a 2-week tour of Mexico for young singles. ...

Severe diarrhea predisposes an individual to metabolic acidosis. Intestinal secretions are high in bicarbonate, so the loss of these fluids through prolonged or severe diarrhea reduces pH levels. In cases of microbial infection, intestinal secretions of bicarbonate are particularly abundant in an attempt to neutralize the metabolic acids of the pathogen. This situation further contributes to a loss of base and development of metabolic acidosis.

The bicarbonate buffer system uses carbonic acid (H2CO3) to substitute a strong acid and a bicarbonate salt to substitute a strong base in the maintenance of serum pH levels. The bicarbonate/carbon dioxide (HCO3/CO2) system is particularly efficient in buffering pH levels because of the ability to quickly form these components in the body and eliminate them as needed.