**Core Concept**
Pseudopolyps are a characteristic feature of chronic inflammatory bowel disease, particularly in conditions like ulcerative colitis. They represent areas of regenerating mucosa that have formed islands or polypoid projections, often in response to chronic inflammation and mucosal injury.

**Why the Correct Answer is Right**
Pseudopolyps are a hallmark of chronic ulcerative colitis, where they form in areas of intense inflammation and mucosal injury. The regenerating mucosa, often with a disorganized architecture, may lead to the formation of polypoid projections. This process is often accompanied by a loss of goblet cells and an increase in Paneth cells. The presence of pseudopolyps can be a useful diagnostic clue in differentiating ulcerative colitis from Crohn's disease.

**Why Each Wrong Option is Incorrect**
**Option A:** Crohn's disease is characterized by skip lesions, cobblestone appearance, and a higher risk of complications like strictures and fistulas, but not pseudopolyps.
**Option B:** Irritable bowel syndrome (IBS) is a functional disorder with chronic abdominal pain, altered bowel habits, and no structural abnormalities, including pseudopolyps.
**Option C:** Diverticulosis is a condition where diverticula form in the colon wall, often due to increased intraluminal pressure, and is not associated with pseudopolyps.

**Clinical Pearl / High-Yield Fact**
When evaluating a patient with chronic diarrhea and colonic symptoms, remember that pseudopolyps are a red flag for ulcerative colitis, and their presence should prompt further investigation, including colonoscopy and biopsy.

**Correct Answer: C. Diverticulosis.**