【Common Diseases】Diarrhea (Diarrhoea)

🥼 What is diarrhea?

Diarrhea refers to an increase in the frequency of bowel movements (generally more than 3 times a day for adults), a significant increase in the water content of the stool (loose or watery stools), or an increase in the weight of the stool .
In Hong Kong, diarrhoea can be categorised into acute diarrhoea (lasting less than 14 days) and chronic diarrhoea (lasting 4 weeks or more).

🔍 Common causes of diarrhea in Hong Kong

Based on information from the Hong Kong Hospital Authority, the Centre for Health Protection and international medical journals, the editor has compiled the following:

1. Acute diarrhea (most common)

  • Viral infection
    • Norovirus and rotavirus outbreaks are common in schools and nursing homes.
  • bacterial infection
    • Salmonella, Escherichia coli (E. coli), Shigella, Vibrio (Cholera, Enteritidis).
  • Food poisoning
    • Hong Kong's hot and humid summers make it easy for food to spoil or become contaminated.
  • parasitic infection
    • Ascaris, Giardia, etc.

2. Chronic diarrhea

  • Irritable bowel syndrome (diarrhea-predominant, IBS-D)
  • Inflammatory bowel disease (IBD)
    • Crohn's disease, ulcerative colitis.
  • Malabsorption
    • Lactose intolerance, celiac disease.
  • Drug side effects
    • Antibiotics, chemotherapy drugs, magnesium salt laxatives, etc.
  • Hyperthyroidism
  • Intestinal tumors

⚠️ Common symptoms and complications

  • Loose or watery stools
  • Abdominal pain and bloating
  • Nausea and vomiting
  • fever
  • Dehydration (thirst, decreased urine output, sunken eyes, poor skin turgor)
  • Bloody stools (indicating intestinal inflammation or bleeding)

🏥 Diarrhea treatment in Hong Kong

Editor's reminder : The key to treating diarrhea is to replenish water and electrolytes, prevent complications, and target the cause .

1. Fluid replacement and maintaining electrolyte balance (most important)

  • Oral rehydration salts (ORS)
    • Available in pharmacies in Hong Kong (such as Hydralyte and Pedialyte), these products are particularly suitable for children and the elderly.
  • Homemade rehydration solution (temporary emergency)
    • 1 litre of boiled and cooled water + 6 level teaspoons of sugar + 0.5 level teaspoons of salt (the proportions must be exact).
  • Avoid dehydrating drinks
    • Strong tea, coffee and alcohol will aggravate dehydration.

2. Dietary recommendations (BRAT principle)

  • Banana : potassium supplement, easy to digest
  • Rice (white rice, porridge): provides energy and reduces intestinal burden
  • Apple sauce: contains pectin, which helps firm the bowels
  • Toast : low in fat and fiber, helps the intestines rest
  • Avoid high-fat, high-sugar, dairy and high-fiber foods (in the short term).

3. Medication (depending on the cause and doctor's instructions)

(1) Antidiarrheal drugs

  • Loperamide: Suitable for non-infectious diarrhea (such as IBS-D), but avoid using it when bacterial infection or bloody stools are suspected to avoid delaying the excretion of pathogens.

(2) Antibiotics

  • Use only when bacterial diarrhea is confirmed and symptoms are severe (eg, Shigella, cholera).
  • Commonly used in Hong Kong: Azithromycin, Ciprofloxacin (doctor's prescription required).

(3) Probiotics

  • Some studies have shown that they can shorten the duration of viral diarrhea (Lactobacillus, Bifidobacterium).

4. Treat chronic diarrhea

  • IBS-D : Antidiarrheal medication, low FODMAP diet.
  • Inflammatory bowel disease : Immunosuppressants or biologics (available in both public and private healthcare).
  • Food intolerances : Avoid allergenic foods (such as lactose).
  • Hyperthyroidism : Controls thyroid hormone levels.

🏥 Hong Kong Examination and Diagnosis Process

Doctors will order tests based on your medical history, symptoms, and course of your illness:

  • Stool examination (culture, parasite screening, occult blood test)
  • Blood tests (inflammatory markers, electrolytes, thyroid function)
  • Colonoscopy (for chronic diarrhea, those with warning symptoms, or those at high risk)
  • Lactose tolerance test

Public healthcare : General outpatient clinic → Internal medicine/gastroenterology and hepatology
Private medical care : faster arrangements for examinations and same-day testing

🚨 Warning symptoms (seek medical attention immediately)

  • High fever (>38.5°C)
  • Bloody or black stools
  • Severe dehydration (very little urine output, extreme thirst, dizziness)
  • Persistent vomiting
  • sudden weight loss
  • Chronic diarrhea with nocturnal symptoms

💡 Editor's Tips

  1. Most cases of acute diarrhea are self-limiting , but the key is to avoid dehydration.
  2. Do not use antidiarrheal medications indiscriminately , especially if infection is suspected.
  3. When eating out, pay attention to hygiene and avoid eating uncooked seafood or raw meat.
  4. Prepare ORS and common medications before traveling , especially to high-risk areas.
  5. Chronic diarrhea should be checked out because it may be an early sign of inflammatory bowel disease or cancer.

💬Editor’s summary :
Diarrhea can occur in Hong Kong in all seasons, but is particularly common in summer and after travel. Most cases of acute diarrhea resolve on their own with rehydration and proper diet. However, if warning signs appear or symptoms worsen, seek medical attention promptly. Chronic diarrhea requires exclusion of serious illnesses and targeted treatment.

📌 Disclaimer <br>This article is for reference only and does not constitute any medical advice. It is sourced from major medical articles.

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