Diarrhea is a condition in which the patient passes loose, watery stool many times a day, often accompanied by a sense of urgency, cramps and stomach upset. Diarrhea can be brought on by bacteria, parasites, disorders of the gastrointestinal tract, medication or food intolerances. In most cases, diarrhea is not a long-lasting or serious condition. However, if it lasts for more than 3 days, is accompanied by a fever, severe abdominal pain or bloody stool, medical consultation is necessary.

Causes of Diarrhea

There are a great many causes of diarrhea and an occasional bout does not usually indicate a serious problem. Ongoing or recurring episodes, however, have to be investigated because they may indicate serious disease. It is also possible that they are simply a result of diet or a mild disease condition, such as irritable bowel syndrome.

Causes of diarrhea include:

  • Viruses, such as rotavirus or norovirus
  • Bacteria, such as salmonella, shigella or E. coli
  • Parasites, like cryptosporidium
  • Medications, particularly antibiotics
  • Lactose or other food intolerance
  • Serious digestive disorders, like Crohn's disease or ulcerative colitis
  • Less serious digestive problems, like irritable bowel syndrome (IBS)
  • Extreme emotional distress

At times, diarrhea is referred to as "travelers diarrhea" because individuals frequently contract bacterial or parasitic infections during trips to countries where sanitation is poor.

Diagnosis of the Causes of Diarrhea

In order to diagnose the cause of diarrhea, the doctor will do a physical examination and review the patient's medical, medication and travel history and any recent dietary changes. Blood tests and stool analysis may also be necessary to make an accurate diagnosis.

Treatment of Diarrhea

In many cases, diarrhea may resolve on its own or with some minimal medication or dietary changes. Taking probiotics during a course of antibiotic treatment, for example, may be all that is necessary to control the problem. Over-the-counter antidiarrheal products may be helpful in relieving temporary symptoms. In all cases of diarrhea, it is necessary to take steps to replace fluids, salts and electrolytes to maintain physical function. In serious cases, or in patients with certain underlying conditions, fluids may have to be administered intravenously.

When bacterial or parasitic causes of diarrhea are diagnosed, patients must be treated with antibiotics or antiparasitics. In most cases of diarrhea caused by viral infections, supportive therapy is the only treatment possible until the virus abates. When diarrhea is caused by an underlying disease condition, a gastroenterologist should be consulted for symptom control and management of the illness.

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