Diarrhea Symptoms, Causes, and Treatment | Daniel Elmatari, PharmD | RxEconsult

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Diarrhea Symptoms, Causes, and Treatments Category: GI (Ulcers, Crohn's, Ulcerative Colitis) by - July 13, 2015 | Views: 42461 | Likes: 0 | Comment: 0  


Diarrhea is the second most common illness suffered by Americans. The most severe cases can result in death by dehydration. Acute diarrhea lasts less than 2 weeks while chronic diarrhea lasts longer than 4 weeks. 

Diarrhea is a change in the looseness of the stool, stool frequency, consistency, urgency and continence. Here is a list of common symptoms of diarrhea, possible causes, and treatments.

Common Symptoms of Diarrhea

Loose or Watery Stools

Diarrhea has a consistency that will take the shape of a container, thus the description of “watery” can be accurately applied. This type of consistency is the hallmark attribute of diarrhea.

Abdominal Cramps

Cramping may be felt anywhere from the chest to the groin.


Diarrhea caused by an infection may be associated with increased body temperature. A body temperature greater than 98.6 F is classified as a fever.


Nausea is a state of uneasiness or discomfort often starting from the stomach and causes the urge to vomit.


Vomiting is the forcible ejection of stomach contents through the mouth. 


Feeling weak, constantly tired or lacking energy are symptoms of fatigue. Usually fatigue will worsen after an episode of diarrhea.


An immediate, unstoppable urge to defecate (evacuate one’s bowels) that requires immediate action. The urge to defecate may also cause nocturnal awakening. 

Weight Loss/Malnutrition

Chronic diarrhea can result in weight loss and malnutrition due to poor absorption of ingested food and loss of nutrients from frequent passage of stool

Bloody Stool

Finding blood in stool(s) could have a range of causes. It is suggestive of serious condition that requires immediate medical attention. 

Causes of Diarrhea

Viruses (Viral Gastroenteritis)

Viruses can attack gut and cause short-term, watery diarrhea. This is often referred to as the stomach flu, The most common viruses in adults are norovirus (“cruise ship diarrhea”) while rotavirus is the main virus that causes children’s diarrhea. There is no treatment for viral gastroenteritis; prevention with proper hand and food hygiene is the best defense.

Bacteria (Travelers’ Diarrhea)

Travelers’ diarrhea (TD) affects 20% to 50% of international travelers. Bacteria is the main source of traveler’s diarrhea and symptoms begin within the first week of travel and most cases resolve within 2 to 7 days without treatment. Escherichia coli, Campylobacter jejuniShigella and Salmonella are the most common bacteria that cause Traveler's diarrhea. Eating only recently cooked meats and seafood, avoiding raw fruits and vegetables, and drinking clean water may help avoid Travelers’ diarrhea but this practice does not always prevent it. The CDC does not recommend prophylactic antibiotics for most travelers. Travelers’ diarrhea is often treated with a a fluoroquinolone antibiotic (for example, Cipro).

Malabsorption or Maldigestion

Fatty diarrhea is caused by malabsorption or maldigestion syndromes. Fatty stool is greasy and very smelly. The pancreas is responsible for releasing digestive enzymes that process foods, and when there is damage to the pancreas (such as alcohol-induced pancreatitis) digestive enzymes are not produced and released in a normal manner. Normal processing and absorption of fats is disrupted, resulting in a larger concentration of fats in stool. Pancreatitis is treated by resting the pancreas from oral food intake, as well as administering intravenous fluids and ceasing alcohol intake. Pancreatic enzymes are available with a prescription for people who lack enough enzymes to properly digest and absorb nutrients.

Other cases of malabsorption include biliary tract obstruction, cholestatic liver disease, and bacterial overgrowth, and small bowel disease.

Celiac Disease

The most common small bowel disease in the United States is celiac disease. Celiac disease is an autoimmune disease that occurs when the immune system causes damage to the small intestine after eating gluten. The damage to the small intestine can result in a decreased ability to absorb nutrients from food, resulting in diarrhea. The treatment for celiac disease is permanent lifestyle modification that revolves around a gluten free diet.

Lactose Intolerance

Watery diarrhea, abdominal bloating, and excessive gas after dairy consumption is most likely due to lactose intolerance. People of Asian and African decent have higher rates than other ethnic groups.  The recommended treatment is a reduction in the amount of dietary lactose along with an over-the-counter lactase supplement whenever dairy is eaten.

Sorbitol and Fructose Intolerance

Watery diarrhea caused by gums, juices, soft drinks and dried fruits may be caused by sorbitol or fructose intolerance. Sorbitol and fructose are types of sugar found in some of these items. Stopping the offending agents is the best treatment for diarrhea associated with sorbitol or fructose intolerance.


Diarrhea is a common side effect of many medications. Diarrhea caused by medications resolves after the medication is stopped. Patients may also develop tolerance to the diarrhea side effects of chronic medications.  


Giardia is an intestinal parasite that causes chronic diarrhea. It is often acquired from contaminated water supplies, but may also be found in food and soil. Giardia infection is effectively treated with metronidazole (Flagyl).


Patients with poorly-controlled blood sugar may develop chronic diarrhea from overgrowth of gut bacteria. Bacteria feeds on sugar, so an excess of sugar can cause gut bacteria to grow to larger amounts than normal.  This disruption in normal gut bacteria can cause diarrhea, as well as nerve damage caused by excessive amounts of sugar circulating in the blood. Reducing blood sugar levels through diet, exercise and medications alleviates diabetes-associated diarrhea.

Irritable Bowel Syndrome (IBS) and Other Digestive Disorders

Approximately 10% to 15% of Americans have IBS. Diarrhea is a common IBS symptom and is often accompanied with abdominal pain. Although the exact cause is unknown, IBS is associated with intestinal inflammation, abnormal serotonin levels, and intestinal bacteria overgrowth. Xifaxan and Viberzi are used for treating IBS diarrhea.

Crohn’s disease, ulcerative colitis, and microscopic colitis are serious conditions that cause chronic diarrhea. 

General Treatments for Diarrhea

Treating diarrhea involves treating the underlying cause of diarrhea, fluid replacement, and using medications to reduce symptoms.


In most cases around the world, dehydration is the leading cause of death. Drinking pure water may be an acceptable form of rehydration for short-term (acute) diarrhea, but for long-term (chronic) diarrhea a solution containing electrolytes is the preferred option. Oral Rehydration Salts solution (ORS), developed by the World Health organization (WHO), has an appropriate concentration of electrolytes and sugar. Over the counter rehydration solutions such as Pedialyte are similar to ORS.

Over The Counter (OTC) Drugs

Anti-diarrheal drugs such as bismuth subsalicylate (Pepto-Bismol) and loperamide can help reduce severe symptoms. These drugs are not recommended for every type of diarrhea and should not be used in the presence of fever or for treating bloody diarrhea. Slowing gut movement can cause bacteria and other infectious agents to remain in the gut for longer and cause more serious problems. Bismuth subsalicylate should not be used in children under 12 due to the risk of Reye’s syndrome, which affects various organs and can result in death.

References & Resources

Gastroenterology Information American College of Gastroenterology

Giardia CDC.gov

Travelers’ Diarrhea CDC.gov

Oral Rehydration Salts WHO.int

Bismuth Subsalicylate nlm.nih.gov

Celiac Disease celiac.org

Viral gastroenteritis mayoclinic.org


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