Diarrhea is an abnormal increase in the frequency, fluidity, and volume of bowel movements. More than three soft, loose, or watery bowel movements in a day constitute diarrhea. In a healthy adult, most cases of diarrhea last from 24 to 48 hours and are not serious. Diarrhea can be more dangerous to infants and older people because of an increased risk of dehydration, upsetting body chemistry and depleting important body salts. Left untreated, it can lead to shock. Persistent or severe diarrhea requires medical attention. A sudden onset after years of regularity can suggest a serious digestive disorder, such as colon cancer. Diarrhea accompanied by symptoms such as weight loss, abdominal pain, or rectal bleeding requires a doctor's attention.
Under normal circumstances, the colon absorbs water from food residue, leading to semisolid feces. When the small intestine becomes inflamed, it fails to absorb food and instead secretes additional water and salts into the digestive tract. The colon cannot absorb the excess water, resulting in diarrhea. Most frequently, diarrhea is due to a viral infection or change in diet. Sometimes, it can be traced to changes in the bacterial population of the digestive tract due to taking antibiotics or to foreign travel. Another cause can be increased frequency or intensity of contractions in the digestive tract, causing food to pass too quickly through the colon. Other common causes include food poisoning, gastroenteritis, celiac disease, lactose intolerance, malabsorption, diverticular disease, inflammatory bowel disease, irritable bowel syndrome, anxiety, over consumption of alcohol, and reaction to medications.
Diagnosis and Treatment
If symptoms last longer than 48 hours, it is important to seek medical attention. For moderate cases, the doctor may try to treat the symptoms and observe the person. In more severe cases, the doctor will conduct a physical examination and may order such tests as blood tests, stool analysis, a lower gastrointestinal (GI) series (an x-ray procedure also called a barium enema) and sigmoidscopy, or colonoscopy (examination of the rectum and colon using flexible viewing tubes passed through the anus).
The symptoms of diarrhea provide clues to its cause. Diarrhea accompanied by nausea and vomiting is usually due to gastroenteritis. Bloody diarrhea that last for more than a few days is a sign of inflammatory bowel disease, while mucus is associated with irritable bowel syndrome, inflammatory bowel disease, and cancer. Loose, yellow, greasy, strong smelling feces that are hard to flush are a symptom of malabsorption. Food poisoning, food allergy, drug toxicity, or anxiety can bring on watery diarrhea.
Doctors advise resting and drinking clear fluids until diarrhea subsides. Because watery diarrhea can rapidly cause a loss of body fluids and crucial body salts, oral rehydration fluid may be needed; available over-the-counter at pharmacies, this specially prepared solution contains water, salts, and glucose. Other over-the counter medication may relieve symptoms. In severe cases, the doctor may prescribe drugs that slow intestinal activity and ease cramping. To prevent diarrhea, it is important to wash hands thoroughly after using the toilet and before preparing foods. When diarrhea is due to underlying problems, it is important to seek treatment.
Source: AMA Complete Medical Encyclopedia, Copyright 2003, American Medical Association