What Can Cause Diarrhea: Main Causes of Diarrhea

Diarrhea is loose, watery stool three or more times in one day. Acute diarrhea usually lasts one to two days and resolves on its own, while diarrhea that continues for four weeks or longer is considered chronic and may be a symptom of a chronic disease. Below are the groups of causes that most often explain what can cause diarrhea.

Intestinal infections as a common cause of diarrhea

The most common causes of diarrhea and vomiting are intestinal infection ("stomach flu") and food poisoning. The causative agents can be bacteria from contaminated food and water, viruses (norovirus, rotavirus), and parasites. Rotavirus is the most common cause of acute diarrhea in children. The bacterium Clostridium difficile often multiplies in the intestine after prolonged antibiotic use or hospital treatment. If the cause is an infection, diarrhea may be accompanied by fever, chills, and blood in the stool.

Dietary causes: intolerance and dietary patterns

Diarrhea is caused by food intolerance and allergy — for example, lactose intolerance, in which the digestion of a certain food component is impaired. A separate variant is "travelers' diarrhea" in people visiting countries with questionable water and food quality. If diarrhea resolves within a few days, its cause usually does not need to be investigated.

Medications and other external factors

Diarrhea can be triggered by medications: antibiotics, anticancer drugs, antacids containing magnesium. The side effect is listed in the package insert. Less often, the cause is radiation therapy in the pelvic area or stomach surgery, after which food passes through the digestive tract more quickly.

Chronic intestinal diseases and diarrhea

Chronic diarrhea can be a symptom of Crohn's disease, ulcerative colitis, celiac disease, diverticular disease, and irritable bowel syndrome. Diarrhea can also accompany other diseases — pancreatitis, chronic hepatitis, gallbladder diseases. In exudative diarrhea associated with inflammation and ulceration of the colonic mucosa, blood, mucus, and pus appear in the stool.

When diarrhea is related to stress and functional disorders

Motor diarrhea is associated with increased intestinal motor activity, including under the influence of stress. This variant is typical of irritable bowel syndrome and functional diarrhea: the stool is semi-formed, in small portions, with a volume of no more than 300 milliliters. Chronic diarrhea from various causes may be associated with anxiety disorders and reduces quality of life.

Symptoms for which the cause must be investigated urgently

Diarrhea itself is not dangerous, but its consequences — dehydration and loss of trace elements — can be life-threatening, especially for children, older adults, and people with weakened immunity. The doctor assesses signs of dehydration, asks about medications being taken, may order a stool or blood test for bacteria and parasites, and for chronic diarrhea — additional examinations. Medical attention is sought if in an adult diarrhea lasts more than two days, in a child — more than 24 hours, with severe abdominal pain, a temperature of 38.9 °C and above, blood or pus in the stool, or black tarry stool.

• signs of dehydration: dark, strongly smelling urine or infrequent urination;
• diarrhea lasts more than seven days in an adult or child;
• vomiting continues for more than two days;
• a child under five years old stops drinking or has fewer wet diapers;
• blood in the stool or bleeding from the anus.

On its own it is not a reason to call an ambulance; 103/112 — if you or your child have vomiting of blood or vomit the color of coffee grounds, yellow-green or green vomiting, neck stiffness and pain when looking at bright light, sudden severe headache, sudden severe abdominal pain, bluish, gray, pale or mottled skin, lips and tongue, severe difficulty breathing or frequent short breaths, confusion.

This material is for reference purposes: it describes possible causes of diarrhea and does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer