DIARRHEA

The purpose of the gastrointestinal (GI) tract is to extract fluid and essential nutrients from the food we eat and to eliminate wastes. All the way along the tract, food is propelled by involuntary rhythmic muscular contractions called peristalsis. From the mouth, ingested food proceeds down a straight tube called the esophagus into the stomach. It is here that the process of digestion begins, with stomach acid being secreted to break down food. Enzymes that also facilitate the breakdown of chemicals in food, permitting absorption into the bloodstream, are secreted here and in subsequent sections of the GI tract. From the stomach, food passes into the small intestine, a relatively thin, long (12 feet) tube with three distinct portions: duodenum, jejunum, and ileum. Enzymes from the pancreas and the gallbladder enter at the duodenum and have specific roles in the digestion of food. Generally, several hours later, the remaining food passes from the ileum into the large intestine or colon. The appendix is a pouch of uncertain function close to the junction between the large and small intestines. Water and some remaining nutrients are extracted in the large intestine, before the remains are excreted through the rectum as stool. 

Most of the time, the GI tract functions without problems, but there are a number of ways in which the system can go awry. Diarrhea is a change in the frequency and consistency of bowel movements and is characterized by the abnormally frequent passage of loose or watery stools. Diarrhea can be associated with underlying disease, anxiety, or infection, usually due to a virus in the intestinal tract. Diarrhea can also be a reaction to a medication, food, or alcohol. Drugs that cause diarrhea include antibiotics, antacids containing magnesium such as MAALOX
and MYLANTA, dietary supplements containing magnesium,[1] certain drugs for high blood pressure, all laxatives except the bulk-forming variety (e.g., psyllium and methycellulose), and quinidine, a drug for irregular heartbeat. See a longer list of drugs that cause diarrhea.

Acute or sudden simple diarrhea lasts only a few days and typically improves with or without medication. Even most infectious diarrhea does not require an antibiotic.

According to a telephone survey by the federal Centers for Disease Control and Prevention (CDC), residents of the United States on average experience 0.72 episodes of acute diarrhea each year. The highest rates were among children under the age of five years (1.1 episodes per year), and the lowest among those 65 years and older (0.32 episodes per year),[2] although death rates per case of diarrhea are likely to be disproportionately high in older adults. Focusing on food-borne illnesses alone (not necessarily diarrhea), the CDC has also developed an estimate of 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year.[3]

Despite the heavy promotion and frequent use of ineffective and/or dangerous prescription or over-the-counter drugs, the world standard for hydrating patients with diarrhea is oral rehydration therapy, an essentially free therapy that is at everyone’s fingertips. Many of the deaths in children and older adults described above might have been prevented if the patients had been given oral rehydration solution (ORS) (see box below).

How to Treat Acute Simple Diarrhea

• Do not eat or drink milk and dairy products, fresh fruits and vegetables, coffee, spicy foods, or other food you do not tolerate well.
• Do not consume drinks with a high sugar content, such as grape juice, apple juice, and soft drinks, including cola, ginger ale, and sports drinks.[4]
• Do not eat highly sweetened foods such as candy, ice cream, or Jell-O because they have too much sugar, which can make the diarrhea worse.[4]
• Drink plenty of ORS (see formula in box below). Once you have noticed watery diarrhea in the toilet bowl, you are probably already a liter (slightly more than a quart) dehydrated. This means you should try to catch up with the fluids you have already lost by drinking three to four eight-ounce glasses of ORS over the next several hours. Once you have caught up—this will be apparent because you will be well enough hydrated to pass urine—you should drink at least four additional eight-ounce glasses of ORS every 12 hours until the diarrhea stops. Patients on a fluid- or salt-restricted diet should consult their physicians concerning the use of ORS.
• Do not eat salty foods such as salty soup, potato chips, or peanuts.
• Do not take medication not prescribed or directed by your doctor or other health professional.
• Take your temperature once a day.

When to Seek Help from a Health Professional

• severe diarrhea in an older adult, particularly one who is very weak
• fever above 101°F (38.3°C)
• blood in the stools or black, tarry stools
• diarrhea for more than three days
• a drug taken under the direction of a doctor may be the cause of the diarrhea
• diarrhea accompanied by severe, incapacitating abdominal pain
• diarrhea with severe dehydration, characterized by dizziness while standing, confusion, or unresponsiveness