Diarrhea: Why It Occurs and How to Get Rid of It
Reviewed by Liubov Mykhailivna Shendryk, Gastroenterologist – Doctor of the Highest Category, Candidate of Medical Sciences updated: 21 May 2026
What Counts as Diarrhea and When Loose Stools Need Attention
Diarrhea is defined as frequent (three or more times a day) loose stools that last from a few hours to several weeks depending on the cause. A single episode of loose stool is usually not a cause for concern, but repeated episodes, blood or mucus in the stool, and signs of dehydration require a doctor’s attention.
Main Causes of Diarrhea in Adults
| Cause | Characteristic Features | Examples of Conditions or Factors |
|---|---|---|
| Intestinal infections | Acute onset, often with fever | Viral, bacterial, parasitic infections |
| Dietary factors | Related to food intake | Food intolerance, food poisoning, overeating |
| Medications | Occurs during or after treatment | Antibiotics, certain laxatives |
| Chronic GI conditions | Prolonged or recurring course | Irritable bowel syndrome, inflammatory bowel disease |
| Stress and functional disorders | Related to emotional state | Anxiety, nervousness |
Why Diarrhea Becomes Frequent or Does Not Go Away for a Long Time
Chronic diarrhea lasting more than four weeks may indicate inflammatory bowel disease, irritable bowel syndrome, food intolerance (such as lactose or gluten), chronic infections, or malabsorption. In such cases, it is important not to rely on symptomatic treatment alone but to identify the underlying cause.
Infectious and Bile Acid Diarrhea: Features and Treatment Approaches
| Type of Diarrhea | Possible Causes | Main Principles of Care |
|---|---|---|
| Infectious diarrhea | Viruses, bacteria, parasites | Rehydration, antimicrobial therapy if indicated |
| Bile acid diarrhea | Impaired bile flow, condition after gallbladder removal | Dietary adjustment, bile-acid-binding medications |
How the Cause of Diarrhea Is Diagnosed in the Gastroenterology Department
Evaluation usually includes stool and blood tests and, if needed, an abdominal ultrasound. To assess the lining of the stomach and esophagus, gastroscopy may be needed, and to examine the large intestine, colonoscopy, especially in chronic diarrhea or suspected inflammatory bowel disease.
How Diarrhea Is Treated and What Can Be Done Before Seeing a Gastroenterologist
Before the appointment, it helps to drink enough fluids with electrolytes to prevent dehydration, stick to a light diet, and avoid taking antibiotics on your own. Treatment depends on the cause — from rehydration and diet to specific therapy for the underlying condition. In rare cases of prolonged diarrhea related to intestinal adhesions, a referral for surgery for adhesive disease or general surgery may be needed.
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