Diarrhea is a very common condition for people of all ages. A viral infection, such as the stomach flu, or a bacterial infection most frequently causes diarrhea. Less commonly, diarrhea is associated with an underlying medical condition. Symptoms include the passing of frequent stools that are loose, watery, and soft. Diarrhea may also cause bloating, pain, cramps, and gas.
Most cases of diarrhea are treated at home and resolve in a few days. Maintaining hydration is the goal of home care. Severe diarrhea can be associated with serious medical complications and require hospitalization
Your stomach produces acids to break down food for digestion. Your stomach processes the food you eat into a liquid form. The processed liquid travels from your stomach to your small intestine. The liquid solidifies as it moves through the large intestine, forming a stool. The stool is eliminated from your body when you have a bowel movement.
Diarrhea is most frequently caused by a viral infection, such as the stomach flu. There are many viruses that cause the stomach flu. Rotavirus and Norwalk virus are the most common ones. The viruses are found in contaminated food or drinking water. Poor hand washing frequently spreads the viruses. The viruses can spread among groups of people, such as schools, employers, or families. Symptoms typically appear within 4 to 48 hours after exposure to the virus.
Bacteria are another common cause of diarrhea and cause the most severe symptoms. Bacterial causes include traveler’s diarrhea, food poisoning, handling undercooked meat or poultry, and handling reptiles with the bacteria. Bacteria related conditions typically last from a few days to a week or more, depending on the cause, and can be associated with bloody bowel movements.
Parasites and chemical toxins can cause diarrhea. Parasites are found in contaminated drinking water or swimming pools. Chemical toxins are most frequently contained in seafood, certain medications, and metals including lead, mercury, and arsenic.
Diarrhea is associated with certain medical conditions. Malabsorption syndromes such as lactose intolerance, gluten malabsorption (celiac disease), and other food intolerances can cause diarrhea. Diarrhea is symptom of inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis. Irritable bowel syndrome (IBS) is a very common gastrointestinal disorder that causes alternating periods of diarrhea and constipation. Immune deficiency, such as with HIV or AIDS infection, can also result in diarrhea.
Certain medications can cause diarrhea, especially some antibiotics. Laxatives used to treat constipation can sometimes result in diarrhea. Diarrhea is a common side effect of chemotherapy used to treat cancer.
Less common causes of diarrhea include Zollinger-Ellison Syndrome, neuropathy, and carcinoid syndrome. Diarrhea can be a symptom of colon cancer. It may also occur after gastrectomy, the surgical removal of part or all of the stomach. Further, diarrhea can be a side effect of high dose radiation therapy for cancer.
Your stools may be any color. Passing blood or red stools can be a sign of a severe infection or other medical condition. Black tarry stools may indicate bleeding in the stomach and may not be a sign of infection. Diarrhea is usually not accompanied by a fever. You should contact your doctor if you experience diarrhea with a fever, bloody stools, or black tarry stools.
Diarrhea can cause dehydration from loss of fluids. Dehydration can be severe and life threatening. It is especially concerning for infants, children, and older adults. Dehydration can cause sleepiness, thirst, and dry mouth. Infants and children may appear to have sunken eyes. An infant’s fontanels, the “soft spots” on the head, may also appear sunken. They may refuse to eat or drink. Older adults with dehydration may experience behavior changes and confusion. Their skin may appear to be loose. Consult your doctor if you or your loved one experiences signs of dehydration.
Your doctor will review your medical history and conduct a physical examination to determine the cause of your diarrhea in order to provide appropriate treatment. You should tell your doctor about your symptoms, risk factors, travel history, and if you have been around people with similar symptoms.
Your doctor will ask you questions about your lifestyle, diet, bowel movement patterns, and stools to help make a diagnosis. You doctor may order stool tests, blood tests, and urine tests.
Avoid eating greasy foods, fatty foods, and alcohol. Bananas, applesauce, rice, and toast are helpful foods to eat. If you feel too sick to eat, try sucking on ice chips until you can tolerate food.
Your doctor may prescribe antibiotics to treat some types of bacterial infections. However, antibiotics do not work on viruses. Stomach viruses usually go away on their own in a few days. Generally, anti-diarrhea medications should not be given for the stomach flu as they only prolong the infection. You should not take over-the-counter diarrhea medications unless your doctor instructs you to.
Treatments vary for diarrhea caused by other medical conditions. Lifestyle and dietary changes may help some conditions. Ask your doctor for suggestions specific to your condition.
If you have a serious medical condition including HIV, AIDS, diabetes, heart disease, kidney disease, or liver disease, contact your doctor as soon as your diarrhea starts. You may need prompt treatment. You may be at risk for developing complications from diarrhea.
If you travel to underdeveloped countries, drink only bottled water and do not use ice. Ice made with contaminated water can contain bacteria. Eat only well-cooked foods including meats, vegetables, and shellfish. Do not consume dairy products. Do not eat fruit that does not have a peel.
Call your doctor if your diarrhea lasts longer than a few days. You should call your doctor if you experience symptoms including faintness, dizziness, dry mouth, and blood or pus in your stools. More serious symptoms include a swollen or painful abdomen, fever higher than 101°, vomiting that lasts for more than 48 hours, and dehydration. Extreme thirst, dry mouth, little urine production, and a lack of tears are signs of dehydration. The eyes of children and infants may appear sunken. An infant’s fontanels, the “soft spots” on the head, may also appear sunken. You should have someone take you to a hospital emergency room if you are sleepy or unaware of your surroundings.