A change in diet is one of the easiest ways to prevent diarrhea. Certain food products can aggravate or cause diarrhea, whereas others can help prevent it. Paying attention to what is consumed and limiting some choices while seeking out others, can help prevent diarrhea.

The first step is to avoid those foods or drinks that can cause diarrhea, such as:

• Fatty foods. A diet high in fats (e.g., fried foods, pastries, potato chips) can lead to absorption problems in the intestines, making stool soft and greasy.
  
  
• High-fiber foods. Fiber in foods such as bran, beans, fresh fruits and vegetables can add bulk and softness to stool, aggravating diarrhea.
  
  
• Caffeine, alcohol. Alcohol or products containing caffeine (e.g., coffee, soda) can stimulate the passage of stool through the intestines, causing insufficient fluid absorption and diarrhea.
  
  
• Dairy products. An inability to digest lactose in dairy products can increase the wateriness of stool and lead to diarrhea.
  
  
• Unpasteurized products. Products that are not pasteurized (e.g., some cheeses) may contain bacteria that, once consumed, may cause diarrhea.

Patients will also want to gradually add foods or drinks to their diet that can help prevent diarrhea. This includes soft, easily digested foods (e.g., soup, crackers) as well as low-fiber foods (e.g., rice, noodles, white bread, lean meats). The American Dietetic Association recommends the BRAT (banana, rice, applesauce, toast) diet to help prevent overstimulation of the intestines and to help reduce the frequency of bowel movements. Researchers are currently studying whether consumption of probiotic foods (foods that contain good bacteria) can help prevent diarrhea.

For chronic diarrhea caused by an underlying intestinal disorder, such as irritable bowel syndrome (IBS), specific dietary changes may be recommended.

Practicing good hygiene is another way to prevent diarrhea caused by bacterial or viral infection. This includes washing hands with soap and water before eating, when preparing food, after using the bathroom and after coming into contact with surfaces that can harbor diarrhea-causing bacteria (e.g., computer keyboards).

When severe diarrhea is caused by ingesting contaminated food or water while in a foreign country, it is called traveler's diarrhea. This is usually only a problem when visiting developing countries. Visitors to developed nations, such as the United States, Canada, Japan, Australia, New Zealand and most of Europe, are less likely to contract traveler’s diarrhea.

People can lower their risk of infectious diarrhea when traveling.  Patients may receive antibiotics in advance from their physician, depending on the location and duration of travel. In addition, traveler’s diarrhea can be avoided by taking the following actions:

• Eat only hot, well-cooked foods. Avoid food that has been left at room temperature for long periods of time. Meat or shellfish should be hot when served and consumed – do not consume raw or rare meat or fish. Avoid food sold by street vendors.
  
  
• Avoid accidental exposure to contaminated water. Use bottled water when traveling. Avoid ice and tap water, even when brushing teeth, to avoid possible contaminants in the water. Do not let shower water get into the ears or mouth.
  
  
• Choose hot beverages or those in sealed containers. Bottled water, carbonated soft drinks, hot coffee and tea are safe to drink.
  
  
• Avoid raw fruits or vegetables, unless they can be peeled. Fruits or vegetables may have been rinsed with contaminated water.
  
  
• Avoid unpasteurized products. Milk, orange juice or other products that have not been pasteurized (heated during processing to eliminate bacteria), may cause diarrhea.

Overuse of antibiotics should be avoided. Antibiotics are a common cause of diarrhea, since they upset the natural balance of bacteria in the intestines. By avoiding the unnecessary use of antibiotics, a patient can help prevent diarrhea.

Research also shows that breastfeeding infants may help reduce their risk of developing diarrhea. In addition, two new vaccines have recently been developed to prevent infants and children from getting rotavirus, a leading cause of diarrhea in this population.