Causes and Remedies for Loose Stools

"Diarrhea" or "diarrheal syndrome" refers to stools with a higher water content than normal, appearing as soft or watery stools. Diarrhea is also characterized by an increased frequency of bowel movements. Ideally, stool should have a water content of about 70-80%, but in diarrhea, this can exceed 90%.

Types of Diarrhea

Diarrhea can be categorized into three main types.

There are also chronic forms of diarrhea that persist over time.

Mechanism of Diarrhea

The primary mechanism behind diarrhea involves an abnormal function in the intestines.

Normally, the intestines move food and liquid along by the muscle movement called peristalsis, digesting them and adjusting the water content before passing them to the rectum. However, if peristalsis becomes overly active or if the intestines’ ability to regulate water is impaired—often due to influences on the autonomic nervous system—the water content in the stool increases, resulting in diarrhea.

Direct causes can include food poisoning, laxative use, and stress. Chronic diarrhea may be due to nerve-related issues, underlying illnesses, or inflammation from medication side effects.

How to Identify the Cause of Diarrhea

Identifying the cause of diarrhea often depends on when it started.

If diarrhea occurs only after eating certain foods, it may be food-related.

Diarrhea accompanied by fever, nausea, or blood may suggest a more serious condition that requires immediate medical attention.

If diarrhea occurs during stressful situations (e.g., before work) without other symptoms or weight loss, it may be stress-induced.

Preventing Diarrhea and Managing Stress-Related Diarrhea

To prevent diarrhea, avoid overeating foods that can irritate the digestive system. For example, if alcohol consumption causes diarrhea, consider reducing your intake. Lactose intolerance is also more common among Japanese people compared to Westerners, so if dairy products cause loose stools, it may be best to avoid them.

For those prone to diarrhea while traveling, bringing anti-diarrheal medication and avoiding unusual foods can help prevent it. If stress triggers diarrhea, consult a doctor for advice.

When experiencing diarrhea, it’s crucial to stay hydrated by drinking room-temperature water and to wait until the diarrhea subsides. Gradually introduce easily digestible foods like porridge, avoiding fatty or spicy foods.