Diarrhea is a common “nuisance disease” that affects most children and adults at some point in their lives. Most cases of diarrheal illnesses are short-lived and resolve on their own with minimal treatment. However, diarrhea can be quite debilitating, often requiring time off work or school.
What Is Diarrhea?
The World Health Organization (WHO) defines diarrhea as passage of more than three loose or watery stools per day. Diarrhea can be categorized based on the duration of symptoms: acute diarrhea lasts for less than 14 days, persistent diarrhea lasts for more than 14 but less than 30 days, and chronic diarrhea lasts for 30 or more days.
Dysentery is a severe form of diarrhea, defined by the presence of both blood and mucous in the stool and is usually associated with fever and abdominal pain. If you experience signs or symptoms of dysentery, we recommend seeing a physician to receive antibiotic treatment and prevent severe complications due to untreated dysentery.
What Causes Diarrhea?
Infectious diarrhea is most commonly caused by a virus, making it self-limited and only requiring symptom control. Bacteria and protozoa (parasites) are the next common cause of infectious diarrhea; these cases usually require prescription medications. Bacterial infections are responsible for most cases of severe acute community-acquired diarrhea, which is defined as greater than four food stools per day for more than 3 days.
Food-borne illness from spoiled or improperly stored food is another common cause of diarrheal illness. Keeping an accurate food history and identifying occupational or travel-related exposures can point to the cause of your illness or pathogens and help guide treatment.
Infectious diarrheal illness is often caused by unpasteurized dairy products, raw or undercooked meat or fish, and organic vitamin preparations. The timing of the food exposure is also important to determine cause and treatment. For example, experiencing diarrhea within 6 hours of eating suggests preformed toxins of staphylococcus aureus or bacillus cereus — particularly if you also experienced nausea and vomiting. At 8 to 16 hours, clostridium perfringens can be the offending agent. More than 16 hours suggests either viral or other bacterial infections.
Additionally, community-wide outbreaks from poultry, fresh produce, or daycare centers have been associated with salmonella, shigella, cryptosporidium, and giardia. Recent antibiotic use, specially clindamycin and fluoroquinolones, or hospitalization within the past 3 months are major risk factors for C. difficile infection.
When Should I See a Doctor for Diarrhea?
The volume and frequency of diarrhea determines the severity of the illness. Passing six or more unformed stools in 24 hours is considered severe, and requires help from a medical professional. You should also see a doctor if you’re experiencing the following signs and symptoms:
- Severe abdominal pain
- Signs of hypovolemia or dehydration
- Fever greater than 102 degrees Fahrenheit or 39 degrees Celsius
- Diarrhea containing blood or mucus
- History of inflammatory bowel disease or any immunocompromised condition, including those 70 years of age or more, as well as those with HIV
- Symptoms persisting for more than one week
In some cases, microbiologics stool testing is needed to identify a potential bacterial pathogen, inform treatment decisions, and manage complications. Persistent diarrhea that does not respond to treatment also warrants additional testing to identify parasitic organisms and other non-infectious causes.
How Is Diarrhea Treated?
Most mild cases of diarrhea resolve on their own and only require symptomatic treatment. Common treatment includes fluid repletion, nutrition maintenance, and/or diet adjustments. Oral rehydration solutions, such as electrolytes and large amounts of fluids, are ideal for fluid repletion. The goal with this treatment is to prevent dehydration by matching or exceeding the amount of electrolytes and fluids lost from the diarrhea.
Gatorade and broths or soups may be adequate for otherwise healthy individuals who are not already dehydrated. If there are signs of hypovolemia — such as dark yellow or scanty urine, decreased skin turgor, or orthostatic hypotension (low blood pressure) — the patient may require intravenous (IV) fluids for urgent rehydration.
Symptomatic therapy via over-the-counter medications like loperamide (Imodium) is controversial. It should be used cautiously and only in cases where fevers are absent and stools are not bloody, as the medication may prolong the disease or lead to more severe illness. Bismuth salicylate (Pepto Bismol) is another over-the-counter medication that has been shown to significantly reduce unformed stools and reduce the symptoms of abdominal pain.
Using probiotics is another way to treat diarrhea and help with recovery. Probiotics contain beneficial bacteria that assists in maintaining or recolonizing the intestine with non-pathogenic flora. Lactobacillus has been shown to decrease the duration of childhood infectious diarrhea, and saccharomyces boulardii may be effective in decreasing the duration of C. difficile infection in some systematic reviews. No clear frequency or dosage has been identified for probiotics usage, so we recommend sourcing natural probiotics from foods like yogurt and kombucha rather than supplements.
Dr. Soleja’s Dietary Recommendations
During a diarrheal illness, it’s important to focus on a diet that provides adequate nutrition and caloric intake, but is still easy for digestion. The BRAT (bananas, rice, applesauce, toast) diet is one such method. Avoid foods with high fat content, as well as dairy products (except yogurt), which may be difficult to digest due to lactose malabsorption.
Complications of Diarrhea
Complications of severe diarrhea illness stem from the risk of dehydration in volume depletion, which can be life-threatening. Look for signs of volume depletion including low blood pressure, dry mouth, dizziness, fatigue, decreased skin turgor, and decreased urine output. These signs and symptoms may suggest a need for intravenous fluid replacement.
Severe diarrhea can also lead to electrolyte disturbances due to large fluid volume shifts, which can be exacerbated if the patient has chronic kidney, liver, or heart disease.
There are also some rare complications of bacterial diarrheal infections. For example, a specific strain of Shiga toxin-producing E. Coli can cause hemolytic uremic syndrome, which can cause severe kidney injury and hematologic abnormalities with low platelet counts. Similarly, leukemoid reactions where white blood cell counts increase to > 50,000 have been associated with clostridioides difficile infection.
If your diarrhea illness is severe and does not improve on its own in a couple days, schedule an appointment with a medical professional to avoid severe complications.
How to Prevent Diarrhea
Prevention can play a key role in decreasing the morbidity from a diarrheal illness. Here are some recommendations:
- Make sure that all consumed food is properly refrigerated and heated. Failure to do so creates a perfect environment for bacterial toxin formation.
- Avoid unnecessary use of antibiotics. Diarrhea is a common side effect of most antibiotics and excessive use of antibiotics leads to bacterial resistance.
- Especially while traveling to underdeveloped areas, drink only purified or bottled water. Drinking from lakes, rivers, or streams can also be quite risky because of unknown pathogens that can be in the water supply.