Choice A rationale:

"In gastroenteritis, diarrhea is often bloody and mucus-filled.”.

This statement is incorrect.

While gastroenteritis can cause loose stools, they are usually watery rather than bloody or mucus-filled.

Bloody or mucus-filled stools might indicate other gastrointestinal issues that need further evaluation.

Choice B rationale:

"Diarrhea in gastroenteritis is typically chronic and persistent.”.

This statement is incorrect.

Gastroenteritis often presents with acute symptoms, including sudden onset of diarrhea, vomiting, and abdominal pain.

Chronic and persistent diarrhea might suggest other chronic gastrointestinal conditions but is not characteristic of gastroenteritis.

Choice C rationale:

"Gastroenteritis usually presents with constipation.”.

This statement is incorrect.

Gastroenteritis typically presents with diarrhea, not constipation.

Constipation is the opposite of diarrhea and is not a symptom associated with gastroenteritis.

Choice D rationale:

"The diarrhea in gastroenteritis is usually watery.”.

This statement is correct.

Watery diarrhea is a hallmark symptom of gastroenteritis.

It results from inflammation of the gastrointestinal tract, leading to increased water content in the stools.

This type of diarrhea can quickly lead to dehydration if not managed promptly.