Causes of Diarrhea in Seniors

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Diarrhea happens to almost everyone -- whether you're 18, 80, somewhere inbetween or beyond. The myriad causes remain fundamentally the same throughout adulthood, although some are more likely during your senior years compared to when you were younger. Age-related changes in your immune, digestive and circulatory systems, and the increased risk for certain medical conditions and their treatment influence the most likely causes of diarrhea during your senior years. As a discussion of all possible causes of diarrhea in seniors is beyond the scope of this article, the focus will be on the most likely and significant causes of diarrhea in older adults.



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Food Poisoning and Traveler's Diarrhea

Food poisoning and other digestive system infections are a frequent cause of sudden, or acute, diarrhea in adults of all ages. Outbreaks of viral gastroenteritis, commonly called the stomach flu, occur most often during the winter months and may affect places with large numbers of older adults, such as community centers and residential healthcare or assisted-living facilities. Among globetrotting seniors, traveler's diarrhea is a common culprit for acute diarrhea with most cases caused by bacterial contamination of food or water.

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Clostridium Difficile

Older adults, particularly those older than 65, are particularly susceptible to diarrhea caused by Clostridium difficile bacteria, also known as C. difficile. Typical symptoms include watery diarrhea, nausea, loss of appetite, fever, abdominal pain and bloating. Major risk factors include:

  • Current stay in a healthcare facility or discharge within the past 12 weeks
  • Recent or current antibiotic treatment
  • Recent or current treatment with stomach-acid-suppressing medication, especially proton pump inhibitors such as esomeprazole (Nexium), lansoprazole (Prevacid) and omeprazole (Prilosec)


Bowel Disorders

A variety of bowel disorders can lead to acute or ongoing diarrhea in older adults.


Diverticulitis describes inflammation of outpouchings of the colon called diverticula, which are present in 50 percent of adults 60 or older and 70 percent of those 80 or older, according to an August 2016 "Mayo Clinic Proceedings" review article. Approximately 1 to 5 percent of adults with diverticula experience at least one bout of diverticulitis, with abdominal pain, fever and diarrhea or constipation.


Ischemic Colitis

Ischemic colitis refers to colon injury caused by decreased or interupted blood supply. This condition most frequently occurs in people older than 65 and is characterized by sudden abdominal pain followed by bloody diarrhea possibly accompanied by nausea, vomiting and bloating.

Bowel Obstruction and Fecal Impaction

Obstruction of the small or large bowel tends to disproportionately affect seniors largely due to age-related risk factors, including prior abdominal or pelvic surgery and digestive system tumors. Diarrhea is particularly prominent with a small bowel obstruction. Other possible symptoms with a bowel obstruction include abdominal pain, nausea, vomiting and bloating.



Large bowel obstruction caused by a fecal impaction -- hardened stool lodged in the colon -- also frequently leads to watery diarrhea as bowel fluid leaks around the impaction. This condition typically develops in people with ongoing, severe constipation, which tends to affect older adults in greater numbers than their younger counterparts.

Other Bowel Disorders

Several other bowel disorders that affect adults of all ages can cause diarrhea in seniors. Examples include:


  • Lactose intolerance
  • Crohn disease
  • Ulcerative colitis
  • Celiac disease
  • Gastric bypass surgery
  • Colon cancer
  • Radiation enteritis after radiation therapy for abdominal or pelvic cancer

Other Causes

More than 700 medications can potentially cause diarrhea, as reported in a May 2008 "Geriatric Gastroenterology" review article. Medication-related diarrhea tends to disproportionately affect seniors, who typically take more medicines than younger adults. Common culprits include antibiotics, laxatives, antacids, stomach acid reducers, blood pressure medicines, cancer drugs, HIV medications and nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin) and naproxen (Aleve).


Medical disorders that can directly or indirectly affect bowel function are another consideration when diarrhea develops in later adulthood. Examples include:

  • Diabetes
  • Appendicitis
  • Pancreatitis (inflammation of the pancreas)
  • Pancreatic cancer
  • Excessive alcohol consumption
  • Pelvic abscess (a pocket of infection and pus in the pelvis)
  • Cirrhosis of the liver
  • Carcinoid tumors (rare, hormone-secreting tumors that cause diarrhea and other symptoms)


Next Steps, Warnings and Precautions

Compared to younger adults, seniors are more vulnerable to the negative effects and complications of diarrhea, including:


  • Dehydration and a related drop in blood pressure
  • Malnutrition and weight loss
  • Electrolyte imbalances, such as sodium and potassium
  • Mental deterioration

Call your doctor right away if you're a senior and experience 3 or more watery stools in a 24-hour period. Seek urgent medical care if you have diarrhea and experience any accompanying warning signs or symptoms, including:

  • Dizziness, lightheadedness or fainting
  • Bloody stool or passing blood from your rectum
  • Inability to keep down fluids
  • New, severe or worsening abdominal pain
  • Confusion or another mental change
  • Fever or chills

Don't ignore the development of diarrhea even if it is not interfering with your daily life because some causes might pose a serious threat to your health. See your doctor as soon as possible to determine the underlying cause and best treatment.

Reviewed and revised by: Tina M. St. John, M.D.




Is this an emergency? If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911.

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