Diarrhea: 10 Risk Factors You Need To Check





Diarrhea is the abnormal increase of liquid in stool and an increase in the frequency of passing stool (defecation).

It is not a distinct illness but a condition that occurs due to other diseases, medications, toxic substances, or cancer therapy.

The name diarrhea comes from a Greek word that means “to flow through.” A person with diarrhea has watery or loose stools more than three times a day.

Other symptoms include cramping, pain, feeling the urge to defecate, irritating the skin around the anus (perianal), and inability to control defecation (fecal incontinence).

Diarrhea lasting two weeks or less is called acute diarrhea; diarrhea lasting for longer than two months is called chronic diarrhea.

Viral and bacterial infections are the most common causes of acute diarrhea. Chronic diarrhea may be caused by Crohn’s disease, ulcerative colitis, diet, certain medications, diabetes, gluten intolerance, or alcohol abuse.

In addition to the frequency of bowel movements, researchers have found that diarrhea best correlates with an increase in stool weight; stool weights above 10 ounces (oz.) (300 grams [g]) per day generally indicate diarrhea.

This weight is mainly due to excess water, which normally makes up 60%–85%of fecal matter.

In this way, true diarrhea is separated from diseases that affect only an increase in bowel progress (hyper defecation) or incontinence (involuntary loss of bowel contents).

Doctors also distinguish between osmotic diarrhea, in which water is drawn into the lumen of the intestines because of an unabsorbable substance (such as some artificial sweeteners), and secretory diarrhea, in which an irritant (usually a bacterium) causes the cells lining the intestine to secrete fluid into the lumen actively.


Diarrhea caused by infections (including parasites) or food poisoning is common in all age groups worldwide.

Acute infectious diarrhea has a huge impact around the world, generating over 5 million deaths per year.

Although most deaths are among children under five years of age in developing nations, the impact is considerable even in developed countries.

For example, over 128,000 individuals are admitted to hospitals in the United States each year because of an episode of acute diarrhea caused by foodborne illness.

The Centers for Disease Control and Prevention (CDC) estimates that 30%–70%of travelers every year get “traveler’s diarrhea,” depending on the destination and the time of year.

Viral infections most commonly cause diarrhea in children. Rotavirus commonly causes diarrhea in children, but US cases have declined since the vaccine was introduced in 2006.

The World Health Organization (WHO) evaluates there are about 550 million cases of diarrhea related to food poisoning each year.

Approximately 10% of patients with advanced cancer suffer from diarrhea, but diarrhea can occur in 50%–80%of patients as a side effect of chemotherapy.

Diarrhea is equally common among both sexes and all races and ethnic groups around the world.


In multiple cases, acute infectious diarrhea is a mild, limited annoyance. Diarrhea can be, however, a debilitating condition that significantly affects a person’s quality of life.

Diarrhea can prevent patients from participating in social activities and going to work. Persons with diarrhea fear soiling their clothing or bed linens, which prevents them from leaving home.

Loss of sleep due to nighttime diarrhea can cause fatigue, ultimately affecting the patient’s ability to function normally.

Uncontrolled diarrhea can lead to chemical imbalances, loss of fluids (dehydration), and even death.

Fast diagnosis and proper therapy can stop much of the suffering connected with these devastating diseases.

Chronic diarrhea as well has a considerable effect on health, as well as on social and economic well-being.

Subjects having celiac disease, inflammatory bowel disease, and another extended diarrheal disease develop nutritional inadequacy that lessens growth and immunity.

They impact social interaction and result in the loss of many working hours.

Risk factors

Risk factors for diarrhea include:

  • frequent travel to countries or wilderness areas with poor sanitation
  • lack of proper precautions in food purchasing, storage, and preparation
  • history of chronic gastrointestinal disorders, including Crohn’s disease and irritable bowel syndrome
  • taking certain medications, particularly antibiotics
  • receiving chemotherapy or radiation therapy for cancer
  • exposure to rotavirus infection
  • having surgery for gallbladder removal or other surgery in the abdomen
  • history of heavy alcohol intake
  • lactose intolerance
  • heavy consumption of foods containing sorbitol, mannitol, and other artificial sweeteners



Diarrhea arises because more fluid travels through the large intestine (colon) than that organ may ingest.

Principally, the colon can absorb a couple of times more fluid than is needed daily.

Albeit, when this retain capacity is overpowered, diarrhea happens.

Diarrhea is created by infections or diseases that lead to surplus creation of fluids or hamper absorption of fluids.

Still, some substances inside the colon, such as fats and bile acids, may meddle with water consumption and create diarrhea.

Furthermore, quick passage of material through the colon may also do the same.

Symptoms connected to any diarrheal diseases are mostly those connected with any damage to the gastrointestinal tract, like fever, nausea, vomiting, and stomach pain. 

All or nothing of these may be presently relying upon the illness producing diarrhea. The number of bowel advancing may vary—up to 20 or more a day.

In certain patients, blood or pus is present in the stool. Bowel movements may be difficult to flush (because they float) or have undigested food material.

The most prevalent causes of acute diarrhea are infections (the cause of traveler’s diarrhea), food poisoning, and medications.

Medications, especially antibiotics and antacids, are a frequent and often overlooked cause.

No so often, diverse sugar-free foods that occasionally contain inadequately absorbable materials induce diarrhea.

Chronic diarrhea is often due to many of the same things that cause the shorter episodes (infections, medications, etc.), but the symptoms last longer.

Some infections can become chronic. These occur mainly with parasitic infections (such as Giardia)or when patients have altered immunity (AIDS).

The following are the more common origins of chronic diarrhea:

  • AIDS
  • colon cancer and other bowel cancers
  • endocrine or hormonal anomalies (thyroid, diabetes mellitus, etc.)
  • food allergic reaction
  • inflammatory bowel disease (Crohn’s disease and ulcerative colitis)
  • lactose intolerance
  • malabsorption syndromes (celiac and Whipple disease)
  • other (alcoholism, microscopic colitis, radiation, surgery)


The most usual cause of diarrhea in cancer patients is related to constipation or its treatment.

Cancer patients may experience diarrhea due to their treatment, or it can be due to dietary changes, infections, hormone imbalances, digestion disorders, or inflammation.

Treatment-related diarrhea can be caused by chemotherapy, hormone therapy, radiation therapy, biological response modifiers (drugs that improve the patient’s immune system), or surgery.

In addition, cancer patients may develop temporary lactose intolerance, which causes diarrhea.

Chemotherapy drugs kill the quickly growing tumor cells. However, some normal cells of the body are rapidly growing, and they too are affected.

Rapidly growing cells are found in the intestines as well as in other parts of the body. Diarrhea occurs as a result of injury to the cells of the intestine.

These effects are temporary.

Chemotherapy drugs, hormones, and biological response modifiers that frequently cause diarrhea include:

  • dactinomycin
  • daunorubicin
  • diethylstilbestrol diphosphate
  • doxorubicin
  • fluorouracil
  • flutamide
  • hydroxyurea
  • interferon
  • interferon-2 (aldesleukin)
  • irinotecan
  • methotrexate
  • thioguanine

Radiation therapy can cause diarrhea if the intestines are in the treatment field. Diarrhea results from the injury and destruction of the cells lining the intestines, which leads to a decrease in the uptake (absorption) of fluids and an increase in the speed with which stool moves through the intestines.

Radiation therapy can cause diarrhea and other intestinal problems many months or years after treatment has been completed.

Diarrhea usually develops within one week following pretreatment (chemotherapy and irradiation) for bone marrow transplantation.

This diarrhea usually disappears within two weeks. Also, bone marrow transplant patients with graft-versus-host disease develop severe diarrhea.

Symptoms and complications

The big effects of diarrhea are dehydration, poor nutrition, and weight loss.

Indication of dehydration can be hard to notice. Still, increasing thirst, dry mouth, weakness or lightheadedness (particularly if worsening on standing), or a dark color/decrease in urination frequency are suggestive.

Serious dehydration leads to changes in the body’s chemistry and may become life-threatening.

Dehydration from diarrhea may result in kidney failure, neurological disorder symptoms, arthritis, and skin issues.


Nearly all cases of acute diarrhea never demand diagnosis or treatment, as most are mild and give few problems.

However, patients with fever exceeding 102°F (38.9°C), hints of dehydration, bloody guts movements, hard abdominal pain, known immune disease, or prior use of antibiotics need prompt medical evaluation.

The doctor will take a patient’s history that includes occupation and recent travel to countries with poor sanitation or wilderness areas.

The doctor will ask what the patient has eaten recently and how much; whether the patient has lost weight; whether the patient has felt dizzy or unusually drowsy; when the patient last had a bowel movement and what its appearance was like;

whether the patient noticed any blood in or on the stool when the patient last urinated, and the amount of fluid taken in the past 24 hours, and whether the patient presently feels feverish.

In some cases, the doctor will ask about the patient’s customary diet, medications that the patient may be taking, and herbal remedies or alternative therapies that the patient may be using.

Chronic diarrhea is quite different from acute diarrhea, and most patients with this illness will receive some level of testing.

Countless exams are the same as for an acute episode and for some infections and parasites causing both types of diarrhea.

A cautious history to decide medication usage, dietary changes, family history of diseases, and other symptoms is required.

Key points in deciding the seriousness of symptoms are weight loss of over 10 pounds (lb.) (4.5 kilograms [kg]), blood in the stool, and nocturnal diarrhea (symptoms that awaken the patient from sleep).

Both prescription and over-the-counter medications can contain such additives as lactose and sorbitol, which will induce diarrhea in sensitive people.

Analysis of allergies or skin changes may also point to a cause. Social history may indicate whether stress is playing a role or identifying activities connected with diarrhea (for example, diarrhea that occurs in long-distance runners).


The doctor will first look for signs of dehydration during an office examination for a patient with diarrhea.

A healthcare professional or observant adult can usually tell by looking at someone who is moderately or severely dehydrated.

Such visual signs as sunken eyes and dry skin are often enough to begin treatment. The doctor will typically examine the skin lining of the patient’s mouth for evidence of dehydration.

In addition, the patient’s blood pressure may be low, breathing or pulse rate may be rapid, and he or she may have a fever.

The doctor will also palpate (gently feel) the patient’s abdomen and listen to bowel sounds through a stethoscope.

In most cases, the doctor will also perform a rectal examination in the office and take a stool sample.


When diagnostic research studies are required, the most beneficial are stool culture and examination for parasites; albeit, these are frequently negative, and a culprit cannot be found in a huge number of patients.

The sooner cultures are performed, the higher the chance of getting a positive result. 

For people with a history of antibiotic application in the previous two months, stool samples need to be tested for the toxins which cause antibiotic-associated colitis.

The analysis is also available to check stool samples for microscopic amounts of blood and cells that indicate severe inflammation of the colon.

Tests to inspect changes in blood chemistry (potassium, magnesium, etc.) and a complete blood count (CBC) are also often performed.


Examination with an endoscope is sometimes helpful in determining the severity and extent of inflammation in cases of severe acute diarrhea.

A mix of stool, blood, and urine tests may be required to assess chronic diarrhea; furthermore, several endoscopic and x-ray studies are frequently required.



Treatment is ideal for fixing the cause; nevertheless, the first goal should be to avoid or treat dehydration and nutritional shortcomings.

The type of fluid and nutrient substitute will depend on whether oral feedings can be taken and the severity of fluid losses.

Of the highest importance in treating diarrhea is the replacement of fluids lost by frequent watery stools.

Patients who can take fluids by mouth should drink six to eight glasses of fluid daily, including clear broth, a ginger ale that has been allowed to go flat, water, weak tea, and commercial formulas that contain sugars and minerals (electrolytes).

Patients with severe diarrhea may need intravenous fluid replacement either at home or in the hospital.

Oral rehydration solution (ORS) or intravenous fluids are the possibilities; ORS is a favorite if possible.

A physician should be alerted if the patient is dehydrated. If oral replacement is suggested, commercial (Pedialyte and others) or homemade preparations can be used.

WHO provides an easy recipe for home preparation, which can be taken in small, frequent sips:

  • table salt—3/4teaspoon
  • baking powder—1teaspoon
  • orange juice—1cup
  • water—1quart (1 liter)

When feasible, food intake should be continued even in those with acute diarrhea. A physician should be consulted as to what type and how much food is permitted.


Antimotility agents (loperamide, diphenoxylate) are useful for those with chronic symptoms; their use is limited or even contraindicated in most individuals with acute diarrhea, especially in those with high fever or bloody bowel movements.

These drugs should not be taken without the advice of a physician.

Other treatments are available, depending on the cause of symptoms. For example, the bulk agent psyllium helps some patients by absorbing excess fluid and solidifying stools; cholestyramine, which binds bile acids, is effective in treating bile salt–induced diarrhea.

Low-fat diets or more easily digestible fat is useful in some patients. New antidiarrheal drugs that decrease the excessive secretion of fluid by the intestinal tract offer another approach for some diseases.

Avoidance of medications or other known products to cause diarrhea (such as lactose) is curative in some patients but should be discussed with a physician.

Cancer patients with chronic diarrhea may be given atropine sulfate (Lomotil), codeine phosphate, loperamide (Imodium), or octreotide (Sandostatin);

however, these drugs should not be taken until the bacterial infection has been eliminated as a cause of diarrhea.

Cancer patients who are experiencing diarrhea due to graft-versus-host disease will continue to take their immunosuppressant drugs.

They may also be treated with corticosteroids and antidiarrheal medications.


It is essential to find the cause of diarrhea since stopping diarrhea when it is the body’s way of eliminating something foreign is not helpful and can be harmful in the long run.

One effective alternative approach to preventing and treating diarrhea involves oral supplementation of the normal flora in the colon with the yeasts Lactobacillus acidophilus, L. Bifidus, or Saccharomyces boulardii.

In clinical settings, these biotherapeutic agents have repeatedly been helpful in the resolution of diarrhea, especially antibiotic-associated diarrhea.

Nutrient replacement also plays a role in preventing and treating episodes of diarrhea. Zinc especially appears to affect the immune system, and deficiency of this mineral can lead to chronic diarrhea.

Also, zinc replacement improves growth in young patients. Plenty of fluids, especially water, should be taken by individuals suffering from diarrhea to prevent dehydration.

The BRAT (bananas, rice, applesauce, and toast) diet also can be useful in helping to resolve diarrhea.

These foods provide soluble and insoluble fiber without irritation. If the toast is slightly burnt, the charcoal can help sequester toxins and pull them from the body.

Acute homeopathic remedies can be very effective for treating diarrhea, especially in infants and young children.

A cancer treatment team at Duke University in North Carolina reported in 2009 that relaxation techniques and electroacupuncture effectively relieve diarrhea in some cancer patients.

Herbal remedies for diarrhea include peppermint tea, chamomile tea, valerian capsules, or aloe vera juice, reducing cramping and intestinal spasms.

An Ayurvedic physician may recommend taking equal parts of yogurt and water with fresh ginger or a powder of beleric myrobalan fruit.

Other Ayurvedic practitioners recommend as many as 28 different plants to treat diarrhea, including buckthorn, jujube, and several plants related to yams.

Ginger capsules may relieve intestinal spasms and pain. Glutamine supplements may speed up the healing process and relieve irritated intestines.

Personal care

Diarrhea can cause the perianal skin to become irritated and painful; therefore, it needs to be cleaned thoroughly after each episode of diarrhea.

Baby wipes or a mild soap with water can be used to clean the irritated skin. The area should be patted dry and occasionally exposed to air.

Taking a sitz bath (sitting in a bathtub of shallow water) with lukewarm water may relieve the discomfort.

Petroleum jelly or another type of barrier cream may be used after cleansing the irritated area.


Prognosis is related to the cause of diarrhea; for most individuals in developed countries, acute infectious diarrhea is at best uncomfortable.

However, in both industrialized and developing areas, serious complications and death can occur.

According to WHO, 525,000 children under five die each year around the world from diarrheal disease.

For those with chronic symptoms, an extensive number of tests are usually necessary to make a proper diagnosis and begin treatment; a specific diagnosis is found in 90% of patients.

However, no specific cause is found, and only treatment with bulk agents or antimotility agents is indicated.

The prognosis of diarrhea in cancer patients is usually related to the prognosis of cancer and the therapies used to treat it.


Proper hygiene and food handling techniques will prevent many cases of diarrhea.

Rotavirus infections in small children can be prevented by a vaccine introduced in 2006. The most important action is to prevent the complications of dehydration.

It is difficult to prevent all cases of traveler’s diarrhea, although, with care, the chances of getting sick can be reduced.

Some commonsense preventive measures include the following:

  • Avoid tap and well water, including ice cubes in drinks.
  • Avoid raw unpeeled fruits and raw vegetables.
  • Avoid unpasteurized milk, dairy products (e.g., ice cream, yogurt), and unpasteurized fruit juices.
  • Do not buy food from street vendors.
  • Wash hands often in uncontaminated water.
  • Choose hot drinks such as coffee or tea or canned or bottled drinks
  • In wilderness situations, travelers should boil water for three to five minutes (depending on elevation); filter water with appropriate filters, or use chlorine bleach (two drops per quart) or tincture of iodine (five drops per quart) in the water.

For cancer patients, some measures can prevent diarrhea related to anticancer treatments.

Patients receiving abdominal radiation therapy can be placed in certain positions to minimize exposure of healthy intestines to radiation.

Diarrhea caused by chemotherapy cannot be prevented; however, the administration of atropine during treatment with irinotecan may prevent diarrhea.

Patients should stop taking dietary supplements, as these can cause diarrhea.

Specific advice about foods to choose and foods to avoid can be found on the American Cancer Society (ACS) website at the link listed below.


  • What is causing diarrhea?
  • Is diarrhea acute or chronic?
  • Can I take care of fluid intake at home, or will I need professional medical treatment to prevent dehydration?
  • What medications, if any, would you recommend?
  • Will I need to make changes in my usual diet?



Berger, Stephen. Escherichia coli Diarrhea: Global Status. 2019 ed. Los Angeles: Gideon Informatics, 2019.

Centers for Disease Control and Prevention. CDC Yellow Book 2020: Health Information for International Travel. New York: Oxford University Press, 2019.

Stern, Scott D. C., Adam S. Cifu, and Diane Altkorn, eds. Symptom to Diagnosis: An Evidence-Based Guide. 4th ed. New York: McGraw Hill Professional, 2019.


Goldenberg, Joshua Z., et al. “Probiotics for the Prevention of Clostridium difficile–Associated Diarrhea in Adults and Children.” Cochrane Database of Systematic Reviews 2017, no. 12 (December 2017).

Guevara, Eduardo Yepez, et al. “Ribotypes Matter: Significance of Clostridium difficile Ribotypes in Cancer Patients with Diarrhea.” Open Forum Infectious Diseases 4, no. S1 (2017): S386–S387.

Schiller, Lawrence R., Darrell S. Pardi, and Joseph H. Sellin. “Chronic Diarrhea: Diagnosis and Management.” Clinical Gastroenterology and Hepatology 15, no. 2 (February 2017): S13–S16.


Diarrhea: Cancer-Related Causes and How to Cope.” Mayo-Clinic.orghttps://www.mayoclinic.org/diseases-conditions/cancer/in-depth/diarrhea/art-20044799 (accessed March 23, 2020).

“Gastrointestinal Complications: Diarrhea.” National Cancer Institute. http://www.cancer.gov/cancertopics/pdq/supportivecare/gastrointestinalcomplications/Patient (accessed March 23, 2020).


American Cancer Society, 250 Williams St. NW, Atlanta, GA 30303, 800-227-2345, http://www.cancer.org

American College of Gastroenterology, 6400 Goldsboro Rd., Ste. 200, Bethesda, MD 20817, 301-263-9000, http://gi.org

Centers for Disease Control and Prevention (CDC), 1600 Clifton Rd., Atlanta, GA 30333, 800-CDC-INFO (232-4636), http://www.cdc.gov

International Society of Travel Medicine (ISTM), 1200 Ashwood Parkway, Ste. 500, Dunwoody, GA 30338, 404-373-8282, 404-373-8283, istm@istm.org, http://www.istm.org

National Cancer Institute, 37 Convent Dr., Bethesda, MD 20814, 800-4-CANCER (422-6237), http://www.cancer.gov

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), 31 Center Dr., Bethesda, MD 20892, 301-637-2653, http://www.niddk.nih.gov

World Health Organization (WHO), Avenue Appia 20, 1211 Geneva 27, Switzerland+41 22 791 21 11, info@who.int, http://www.who.int/en