Symptoms and causes

Symptoms

Signs and symptoms associated with diarrhea may include:

  • Loose, watery stools
  • Abdominal cramps
  • Abdominal pain
  • Fever
  • Blood in the stool
  • Bloating
  • Nausea
  • Urgent need to have a bowel movement

When to see a doctor

If you're an adult, see your doctor if:

  • Your diarrhea persists beyond two days
  • You become dehydrated
  • You have severe abdominal or rectal pain
  • You have bloody or black stools
  • You have a fever above 102 F (39 C)

In children, particularly young children, diarrhea can quickly lead to dehydration. Call your doctor if your child's diarrhea doesn't improve within 24 hours or if your baby:

  • Becomes dehydrated
  • Has a fever above 102 F (39 C)
  • Has bloody or black stools

Causes

A number of diseases and conditions can cause diarrhea, including

  • Viruses. Viruses that can cause diarrhea include Norwalk virus, cytomegalovirus and viral hepatitis. Rotavirus is a common cause of acute childhood diarrhea.
  • Bacteria and parasites. Contaminated food or water can transmit bacteria and parasites to your body. Parasites such as Giardia lamblia and cryptosporidium can cause diarrhea.

    Common bacterial causes of diarrhea include campylobacter, salmonella, shigella and Escherichia coli. When traveling in developing countries, diarrhea caused by bacteria and parasites is often called traveler's diarrhea. Clostridium difficile infection can occur, especially after a course of antibiotics.

  • Medications. Many medications, such as antibiotics, can cause diarrhea. Antibiotics destroy both good and bad bacteria, which can disturb the natural balance of bacteria in your intestines. Other drugs that cause diarrhea are cancer drugs and antacids with magnesium.
  • Lactose intolerance. Lactose is a sugar found in milk and other dairy products. People who have difficulty digesting lactose have diarrhea after eating dairy products.

    Your body makes an enzyme that helps digest lactose, but for most people, the levels of this enzyme drop off rapidly after childhood. This causes an increased risk of lactose intolerance as you age.

  • Fructose. Fructose, a sugar found naturally in fruits and honey and added as a sweetener to some beverages, can cause diarrhea in people who have trouble digesting it.
  • Artificial sweeteners. Sorbitol and mannitol, artificial sweeteners found in chewing gum and other sugar-free products, can cause diarrhea in some otherwise healthy people.
  • Surgery. Some people have diarrhea after undergoing abdominal surgery or gallbladder removal surgery.
  • Other digestive disorders. Chronic diarrhea has a number of other causes, such as Crohn's disease, ulcerative colitis, celiac disease, microscopic colitis and irritable bowel syndrome.

Complications

Diarrhea can cause dehydration, which can be life-threatening if untreated. Dehydration is particularly dangerous in children, older adults and those with weakened immune systems.

If you have signs of serious dehydration, seek medical help.

Indications of dehydration in adults

These include:

  • Excessive thirst
  • Dry mouth or skin
  • Little or no urination
  • Weakness, dizziness or lightheadedness
  • Fatigue
  • Dark-colored urine

Indications of dehydration in infants and young children

These include:

  • Not having a wet diaper in three or more hours
  • Dry mouth and tongue
  • Fever above 102 F (39 C)
  • Crying without tears
  • Drowsiness, unresponsiveness or irritability
  • Sunken appearance to the abdomen, eyes or cheeks