**Core Concept**
Drug-induced colitis, also known as antibiotic-associated colitis, occurs when antibiotics disrupt the normal gut flora, allowing overgrowth of pathogenic bacteria such as Clostridioides difficile (C. diff). This condition can lead to severe inflammation and damage to the colonic mucosa.

**Why the Correct Answer is Right**
Clindamycin, a lincosamide antibiotic, is a well-known cause of antibiotic-associated colitis. It inhibits protein synthesis by binding to the 50S ribosomal subunit of bacteria, leading to a reduction in the production of essential bacterial proteins. This disruption of the gut microbiota allows C. diff to overgrow and produce toxins that cause colitis. Clindamycin's broad-spectrum activity against both Gram-positive and Gram-negative bacteria contributes to its high association with antibiotic-associated colitis.

**Why Each Wrong Option is Incorrect**
**Option A:** Neomycin is an aminoglycoside antibiotic that primarily targets Gram-negative bacteria. While it can disrupt the gut flora, its association with antibiotic-associated colitis is lower compared to clindamycin.
**Option B:** Vancomycin is a glycopeptide antibiotic that primarily targets Gram-positive bacteria. It is actually used to treat C. diff infections, rather than causing them.
**Option D:** Chloramphenicol is a broad-spectrum antibiotic that inhibits protein synthesis by binding to the 50S ribosomal subunit, similar to clindamycin. However, it is less commonly associated with antibiotic-associated colitis due to its narrower spectrum of activity and lower gut penetration.

**Clinical Pearl / High-Yield Fact**
To prevent antibiotic-associated colitis, it is essential to use antibiotics judiciously and consider alternative treatments for mild infections. Additionally, patients taking broad-spectrum antibiotics should be monitored for signs of colitis, such as diarrhea, abdominal pain, and bloody stools.

✓ Correct Answer: C. Clindamycin