Most common cause of Traveller’s diarrhoea :
**Core Concept**
Traveller's diarrhoea is a common illness affecting individuals travelling to new destinations, often caused by consuming contaminated food or water. The underlying principle involves the introduction of **pathogenic microorganisms** into the body.
**Why the Correct Answer is Right**
The most common cause of traveller's diarrhoea is **Enterotoxigenic Escherichia coli (ETEC)**, which produces toxins that stimulate the intestinal lining to secrete excessive fluid, leading to diarrhoea. ETEC is commonly found in contaminated food and water in areas with poor sanitation.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect as it is not the most common cause.
**Option B:** Incorrect, though it can cause diarrhoea, it's not the most common cause in travellers.
**Option C:** Incorrect, not typically associated with traveller's diarrhoea.
**Option D:** Incorrect, though a cause of diarrhoea, not the most common in travellers.
**Clinical Pearl / High-Yield Fact**
Remember, **ETEC** is a common cause of traveller's diarrhoea, and prevention involves avoiding contaminated food and water.
**Correct Answer:** D. Enterotoxigenic Escherichia coli (ETEC)