To most persons, diarrhea means an increased frequency or softer consistency of bowel movements; however, the medical definition is more exact than this. Diarrhea best correlates with an increase in stool weight; stool weights above 300 g per day generally indicates diarrhea. This is mainly due to excess water, which normally makes up 60-85% of fecal matter. In this way, true diarrhea is distinguished from diseases that cause only an increase in the number of bowel movements (hyperdefecation), or incontinence (involuntary loss of bowel contents).
Diarrhea is also classified by physicians into acute, which lasts one to two weeks, and chronic, which continues for longer than 23 weeks. Viral and bacterial infections are the most common causes of acute diarrhea.

In many cases, acute infectious diarrhea is a mild, limited annoyance. However, acute infectious diarrhea has a huge impact worldwide, causing over five million deaths per year. While most deaths are among children under five years of age in developing nations, the impact, even in developed countries, is considerable. For example, over 250,000 persons are admitted to hospitals in the United States each year because of diarrhea. Rapid diagnosis and proper treatment can prevent much of the suffering associated with this illness.
Chronic diarrhea also has a considerable effect on health, as well as on social and economic well being. Patients with celiac disease, inflammatory bowel disease, and other prolonged diarrheal illnesses develop nutritional deficiencies, which diminish growth and immunity. They affect social interaction and result in the loss of many working hours.

Causes & symptoms:
Diarrhea occurs because more fluid passes through the large intestine (colon) than can be absorbed. As a rule, the colon can absorb several times more fluid than is required on a daily basis. However, when this reserve capacity is overwhelmed, diarrhea occurs.
Diarrhea is caused by infections or illnesses that either lead to excess production of fluids or prevent absorption of fluids. Also, certain substances in the colon, such as fats and bile acids, can interfere with water absorption and cause diarrhea. In addition, rapid passage of material through the colon can cause diarrhea.
Symptoms related to diarrheal illness are often those associated with any injury to the gastrointestinal tract, such as fever, nausea, vomiting, and abdominal pain. All or none of these may be present depending on the cause of diarrhea. The number of bowel movements can vary with up to 20 or more per day. In some patients, blood or pus is present in the stool. Bowel movements may contain undigested food material.
The most common causes of acute diarrhea are infections (the cause of traveler’s diarrhea), food poisoning, and medications. Medications are a frequent and often overlooked cause, especially antibiotics and antacids. Both prescription and over-the-counter medications can contain additives, such as lactose and sorbitol, that will produce diarrhea in sensitive persons. Less often, various sugar-free foods, which sometimes contain poorly absorbable materials, cause diarrhea. Review of allergies or skin changes may also point to a cause.
Chronic diarrhea is frequently due to many of the same things that cause the shorter episodes (infections, medications, etc.); symptoms just last longer. Some infections can become chronic. This occurs mainly with parasitic infections (such as Giardia), or when patients have altered immunity (such as AIDS).
The following are the more usual causes of chronic diarrhea:
– colon cancer and other bowel tumors
– endocrine or hormonal abnormalities (thyroid, diabetes mellitus, etc.)
– food allergy
– inflammatory bowel disease (Crohn’s disease and ulcerative colitis)
– lactose intolerance
– malabsorption syndromes (celiac and Whipple’s disease)
– other (alcohol, microscopic colitis, radiation, surgery)

The major effects of diarrhea are dehydration, malnutrition, and weight loss. Signs of dehydration can be hard to notice but include thirst, dry mouth, weakness or lightheadedness (particularly if worsening on standing), urine darkening, or a decrease in urination. Severe dehydration leads to changes in the body’s chemistry and could become life-threatening. Dehydration from diarrhea can result in kidney failure, neurological symptoms, arthritis, and skin problems.

Most cases of acute diarrhea never need diagnosis or treatment, as many are mild and produce few problems. But patients with fever over 102?F (38.9?C), signs of dehydration, bloody bowel movements, severe abdominal pain, known immune disease, or recent use of antibiotics need prompt medical evaluation.
When diagnostic studies are needed, the most useful are stool culture and examination for parasites; however these are often negative and a cause cannot be found in a large number of patients. The earlier cultures are performed, the greater the chance of obtaining a positive result. Stool samples of patients who had used antibiotics in the preceding two months need to be examined for the toxins that cause antibiotic-associated colitis. Tests are also available to check stool samples for microscopic amounts of blood and for cells that indicate severe inflammation of the colon. Examination with an endoscope is sometimes helpful in determining severity and extent of inflammation. Tests to check changes in blood chemistry (potassium, magnesium, etc.) and a complete blood count (CBC) may be performed.
Chronic diarrhea is quite different, and most patients with this condition will receive some degree of testing. Many exams are the same as for an acute episode, as some infections and parasites cause both types of diarrhea. A careful history to evaluate medication use, dietary changes, family history of illnesses, and other symptoms is necessary. Key points in determining the seriousness of symptoms are weight loss of over 10 lb (4.5 kg), blood in the stool, and nocturnal diarrhea (symptoms that awaken the patient from sleep). A combination of stool, blood, and urine tests may be needed in the evaluation of chronic diarrhea; in addition a number of endoscopic and x-ray studies are frequently required.

Treatment is ideally directed toward correcting the cause; however, the first aim is to prevent or treat dehydration and nutritional deficiencies. When possible, food intake should be continued even in patients with acute diarrhea. A physician should be consulted as to what type and how much food is permitted. Low-fat diets or more easily digestible fat is useful in some patients. The BRAT diet, which limits food intake to bananas, rice, applesauce, and toast, can help to resolve diarrhea. These foods provide soluble and insoluble fiber without irritation. If the toast is slightly burnt, the charcoal can help sequester toxins and pull them from the body.
The patient should drink plenty of fluids, however, in severe cases hospitalization to provide intravenous fluids may be necessary. A physician should be notified if the patient is dehydrated, and if oral replacement is suggested then commercial (Pedialyte and others) or homemade preparations can be used. The World Health Organization (WHO) has provided this easy recipe for home preparation, which can be taken in frequent small sips:

– table salt: 3/4 teaspoon
– baking powder: 1 teaspoon
– orange juice: 1 cup
– water: 1 quart or liter
Nutrient replacement also plays a role in preventing and treating diarrhea. Zinc especially appears to have an effect on the immune system, and deficiency of this mineral can lead to chronic diarrhea. Also, zinc replacement improves growth in young patients.
Dietary supplements that are generally beneficial in the treatment of digestive disorders include:
– vitamin C: 50-500 mg daily
– vitamin B6: 50-150 mg daily
– magnesium aspartate: 400 mg daily
– vitamin E: 400 IU daily
– glutamine: 3,000 mg daily
– garlic, deodorized: 2,000 mg daily
– deghycirrhizinated licorice: chew as needed
Probiotics refers to treatment with beneficial microbes either by ingestion or through a suppository. Studies and the clinical use of probiotics have shown their utility in the resolution of diarrhea, especially antibiotic-associated diarrhea. Beneficial microbes include the bacteria Lactobacillus acidophilus and L. bifidus and the yeast Saccha-romyces boulardii. To treat diarrhea, the patient can eat one cup of yogurt (containing active Lactobacillus acidophilus

cultures) daily. Alternatively, one or two acidophilus capsules may be taken at each meal or at bedtime.

Shallow acupuncture, when the needles are inserted superficially and rapidly removed, was more therapeutic than drugs in children with acute or chronic diarrhea. In another study, acupuncture eliminated symptoms and normalized stools in children with chronic diarrhea who had not responded to conventional or Chinese medicines.
Herbals and Chinese medicines
Herbal remedies for diarrhea include meadowsweet, goldenseal, and chamomile taken as an infusion throughout the day.
Chinese patent medicines used for treating diarrhea include:
– Xiang Sha Liu Jun Wan (Six-Gentlemen Pill with Aucklandia and Amomum)
– Fu Zi Li Zhong Wan (Prepared Aconite Pill to Regulate the Middle)
– Si Shen Wan (Four-Miracle Pill)
– Wu Mei Wan (Mume Pill)
– Jian Pi Wan (Strengthen the Spleen Pill)
– Shen Ling Bai Zhu Wan (Ginseng, Poria, and Atracty-lodes Macrocephala Pill)

Allopathic treatment:
Anti-motility agents (loperamide, diphenoxylate) are useful for persons with chronic diarrhea; their use is limited or even contraindicated in patients with acute diarrhea, especially in those with high fever or bloody bowel movements. They should not be taken without the advice of a physician. Other treatments that are available, depending on the cause of diarrhea, include the bulk agent psyllium and the binder cholestyramine. Also, new antidiarrheal drugs that decrease excessive secretion of fluid by the intestinal tract are available.

Expected results:
Prognosis is related to the cause of the diarrhea; for most individuals in developed countries, a bout of acute, infectious diarrhea is at best uncomfortable. However, in both industrialized and developing areas, serious complications and death can occur.

Proper hygiene and food handling techniques will prevent many cases. Traveler’s diarrhea can be avoided by use of Pepto-Bismol and/or antibiotics, if necessary.
The most important action is to prevent dehydration, as
outlined above.

Anti-motility medications-Medications such as loperamide (Imodium), diphenoxylate (Lomotil), or medications containing codeine or narcotics that decrease the ability of the intestine to contract. These can worsen the condition of a patient with dysentery or colitis.
Colitis-Inflammation of the colon.
Endoscope-A thin flexible tube that uses a lens or miniature camera to view various internal organs including the gastrointestinal tract. Both diagnosis and therapeutic procedures can be done with this instrument.
Endoscopy-The performance of an exam using an endoscope.
Lactose intolerance-An inability to properly digest milk and dairy products.
Probiotics-The use of beneficial microbes to treat various diseases, including diarrhea.