Diarrhea causes more missed days of work and school than any health problem other than the common cold, according to the Cleveland Clinic. This common malady usually goes away on its own, and fasting won't help resolve it more quickly. In fact, fasting during a bout of diarrhea may be counterproductive. Regardless of food intake, diarrhea that persists with no improvement for two or more days merits a visit to the doctor.
Viral diarrhea caused by rotovirus and norovirus usually takes three to seven days to resolve. Bacterial diarrhea, such as that caused by E. coli infections, may start up to eight days after eating contaminated food and resolve either quickly or slowly. Diarrhea caused by parasites, food sensitivities or allergies, irritable bowel syndrome, intestinal diseases and medications may be intermittent or ongoing and often requires medical treatment to get better. If diarrhea improves within two days and isn't accompanied by other symptoms, there's no need to identify its cause.
You may think that avoiding food will help you recover from diarrhea more quickly, but this is only partly true. It's wise to avoid foods high in sugar, fat and fiber, all of which can make diarrhea worse. Dairy products and caffeinated beverages also tend to irritate an inflamed digestive tract. However, fasting slows recovery because the cells that make up the intestinal lining require food to replenish themselves. It's okay to avoid food for several hours if your stomach is queasy, but as eating small amounts of bland foods as soon as you feel able will help your digestive tract heal. Bananas, soup, and simple starches like potatoes and rice, are good choices. The National Institutes of Health's MedlinePlus service recommends eating some foods that contain salt, such as pretzels and soup, because diarrhea can deplete blood sodium levels.
Drinking plenty of fluids during bouts of diarrhea is crucial, because dehydration is a common and dangerous side effect. Drinking water, juice and sports drinks regularly will keep dehydration at bay. MedlinePlus recommends eight to 10 cups of fluid per day, and at least one cup after each instance of diarrhea. Watered-down fruit juice is an ideal beverage, as it contains potassium that your body needs to maintain a proper fluid balance.
Consult a health care provider if diarrhea lasts for longer than two days with no improvement or if you have a high fever, pain or stools that are bloody, tarry or mucous filled. Dehydration requires urgent medical care. Signs of severe dehydration include dry skin and mouth, dizziness, fatigue and dark urine. Pressing on a fleshy patch of skin, such as on your calf, dehydration is also indicated if the skin depresses and doesn't spring back right away.