**Question:** The therapy of choice for pseudomembranous enterocolitis is

A. Metronidazole
B. Vancomycin
C. Ciprofloxacin
D. Amoxicillin

**Correct Answer:** B. Vancomycin

**Core Concept:**
Pseudomembranous enterocolitis is a clinical condition caused by the overgrowth of Clostridium difficile, a bacterium that produces toxins leading to inflammation and tissue damage in the gastrointestinal tract.

**Why the Correct Answer is Right:**
Vancomycin is a glycopeptide antibiotic that specifically targets gram-positive bacteria, including Clostridium difficile. It works by inhibiting the synthesis of peptidoglycan, a crucial component of bacterial cell walls. By selectively targeting C. difficile, Vancomycin helps alleviate the toxin production and inflammation associated with pseudomembranous enterocolitis.

**Why Each Wrong Option is Incorrect:**

A. Metronidazole (Flagyl): This antibiotic is effective against anaerobic bacteria, but it does not target Clostridium difficile directly. As a result, it may not effectively treat the underlying cause of pseudomembranous enterocolitis.

B. Ciprofloxacin (Cipro): Ciprofloxacin is a fluoroquinolone antibiotic that is effective against a broad range of bacteria, but it does not specifically target Clostridium difficile. Thus, it is less effective in treating pseudomembranous enterocolitis compared to Vancomycin.

C. Ciprofloxacin (Cipro): Similar to the explanation for option B, Ciprofloxacin is also effective against gram-negative bacteria but does not directly target Clostridium difficile. Therefore, it may not be the optimal choice for treating pseudomembranous enterocolitis.

D. Amoxicillin (Amoxil): Amoxicillin is a penicillin antibiotic that targets gram-positive bacteria, but it does not specifically target Clostridium difficile. Consequently, it may not effectively treat the cause of pseudomembranous enterocolitis.

**Clinical Pearl:**
Vancomycin is the preferred treatment for pseudomembranous enterocolitis due to its ability to specifically target Clostridium difficile, which is the primary causative agent in this condition. The other options (Metronidazole, Ciprofloxacin, and Amoxicillin) are effective against certain bacterial infections but do not directly target Clostridium difficile, making them less effective in treating pseudomembranous enterocolitis.