Chronic diarrhea Diarrhea refers to an increase in the frequency of bowel movements, with more than 3 times per day or a total stool weight exceeding 200g, and the stool is watery (containing more than 85% water) or contains mucus, pus, blood, or undigested food. Chronic diarrhea refers to patients with a duration of more than 4 weeks or recurrent long-term episodes of diarrhea.

Diarrhea refers to an increase in bowel movements, with a frequency exceeding 3 times per day or a total stool volume exceeding 200g, characterized by watery stools (containing more than 85% water) or stools with mucus, pus, undigested food. Chronic diarrhea refers to a condition that persists for more than 4 weeks or exhibits recurrent episodes over an extended period.

Chronic diarrhea is caused by a reduction in the intestine's ability to absorb water or an increase in its secretion, leading to an increase in stool water content and subsequent diarrhea.

Based on the pathogenesis, diarrhea can be classified into the following four types:

1. Osmotic diarrhea

Osmotic diarrhea results from the presence of poorly absorbable substances in the intestinal lumen, leading to increased osmotic pressure and the influx of fluid into the intestine, causing an increase in stool water content. Symptoms can be alleviated or stopped by fasting or discontinuing medication, and undigested food or drugs may be visible in the stool.

2. Secretory diarrhea

Secretory diarrhea occurs due to stimulation of the intestinal mucosa, resulting in electrolyte and water imbalance, and excessive secretion of fluid by the intestinal epithelium, leading to diarrhea. Clinical features include:

- Daily stool volume > 1L, sometimes up to 10L

- Stools are watery without pus or blood, often with a neutral or alkaline pH

- Diarrhea does not subside after 48 hours of fasting, with a daily stool volume exceeding 500ml

3. Exudative diarrhea

Exudative diarrhea, also known as inflammatory diarrhea, is caused by infections or non-infectious factors that disrupt the integrity of the intestinal mucosa, resulting in the exudation of large amounts of fluid into the intestine, leading to diarrhea. Clinical features include the presence of mucus and blood in the stool, often accompanied by abdominal or systemic signs of inflammation.

4. Motility-related diarrhea

Motility-related diarrhea occurs due to excessive intestinal motility, leading to rapid passage of food through the intestine, reduced contact time with the intestinal lumen, and impaired water absorption, resulting in diarrhea. Clinical features include urgency, unformed or watery stools, without exudates or blood, usually accompanied by increased bowel sounds or abdominal pain.

The specific pathogenesis of chronic diarrhea is complex, but in simple terms, it involves a reduction in the intestine's ability to absorb water or an increase in its secretion, leading to an increase in stool water content and resulting in diarrhea.

Common causes can be divided into two major categories: digestive system diseases and systemic diseases.

Digestive system diseases include:

- Gastric diseases: chronic atrophic gastritis, post-gastrectomy achlorhydria

- Intestinal infections: intestinal tuberculosis, chronic bacterial dysentery, chronic amoebic dysentery, schistosomiasis, intestinal protozoal diseases, hookworm disease, tapeworm disease, etc.

- Non-infectious intestinal diseases: Crohn's disease, ulcerative colitis, multiple colonic polyps, malabsorption syndrome, etc.

- Intestinal tumors: colonic villous adenoma, intestinal malignancies

- Pancreatic diseases: chronic pancreatitis, pancreatic cancer, post-pancreatectomy

- Hepatobiliary diseases: cirrhosis, cholestatic jaundice, chronic cholecystitis and cholelithiasis

Systemic diseases include:

- Endocrine and metabolic disorders: hyperthyroidism, adrenal insufficiency, gastrinoma, vasoactive intestinal peptide tumor, carcinoid syndrome, and diabetic enteropathy, etc.

- Other systemic diseases: systemic lupus erythematosus, scleroderma, uremia, radiation enteritis, etc.

- Adverse drug reactions: reserpine, thyroxine, digitalis, colchicine, certain anticancer drugs, and antibiotics, etc.

- Neurological dysfunction: such as irritable bowel syndrome, etc.

Patients often present with increased bowel movements, unformed or watery stools, and sometimes with mucus or blood.

For patients with small intestine lesions: discomfort or pain around the navel, usually aggravated after meals or before defecation.

For patients with colonic lesions: discomfort on both sides or lower abdomen, relief of pain after defecation, frequent and urgent bowel movements, small stool volume, often containing blood and mucus.

For patients with rectal lesions: often accompanied by a feeling of incomplete evacuation, small stool volume, and darker stool color.

Diet

Patients with chronic diarrhea should pay attention to a light diet and have small, frequent meals.

Avoid consuming:

- Alcohol

- Caffeine-containing foods and beverages

- Dairy products such as milk, ice cream, etc.

- Fructose-containing drinks and foods

- Fruits such as apples, peaches, and pears

- Sugar-free gum and candies containing sweeteners

- Heavy, salty, and spicy foods

Consume more easily digestible foods such as:

- Fruit juice

- Soda water

- Soda crackers

- Eggs

Lifestyle habits

Develop good personal hygiene habits, wash hands before meals and after using the restroom, and avoid drinking untreated water.

Exercise

Regular physical activity to enhance the body's resistance to disease.

Preventing infection

Increase handwashing frequency, extend handwashing time, and use hand soap to prevent infectious diarrhea.

Diet management

Pay attention to food hygiene and avoid consuming inadequately cooked meats and seafood. When possible, only drink bottled water and consume peeled or thoroughly cooked fruits and vegetables.

Probiotics

Appropriate use of probiotic preparations can effectively reduce the risk of antibiotic-associated diarrhea and chemotherapy-related diarrhea.