Multiple ileal strictures and internal fistulas are features of
First, the core concept here is the pathophysiology of IBD. I remember that Crohn's disease typically affects the terminal ileum and can cause strictures and fistulas. Ulcerative colitis is more about the colon and doesn't usually form fistulas. So the key here is distinguishing between the two.
Why is Crohn's the correct answer? Because it's a transmural inflammation, which leads to thickening of the bowel wall and can cause strictures. The transmural nature also allows for fistulas to form between loops of intestine or other organs. Internal fistulas are a hallmark of Crohn's.
Now the wrong options. Let's say the options are A: Ulcerative colitis, B: Celiac disease, C: Whipple's disease, D: Crohn's disease. Option A is incorrect because UC is mucosal, no fistulas. B is celiac, which causes malabsorption, not strictures. C is Whipple's, which affects small intestine but presents with arthritis and weight loss, not fistulas. So D is correct.
Clinical pearl: Remember that Crohn's has a "skip lesions" pattern, affects any part of GI, stricture, fistulas. UC is continuous from rectum up, no fistulas. That's a key differentiator for exams.
**Core Concept**
Multiple ileal strictures and internal fistulas are hallmark features of **Crohn’s disease**, a type of inflammatory bowel disease (IBD) characterized by transmural inflammation. This inflammation leads to fibrosis and ulceration, which can penetrate the bowel wall, causing fistula formation.
**Why the Correct Answer is Right**
Crohn’s disease commonly affects the terminal ileum and involves all layers of the intestinal wall (**transmural inflammation**). Chronic inflammation leads to **fibroproliferative strictures** due to scarring and **internal fistulas** (e.g., enterocutaneous or enterovesical) from ulceration extending through the bowel wall. These features distinguish it from ulcerative colitis, which is limited to the colon and lacks fistulas.
**Why Each Wrong Option is Incorrect**
**Option A (Ulcerative colitis):** Causes continuous mucosal inflammation of the colon and rectum but does not produce strictures or fistulas.
**Option B (Celiac disease):** Triggers villous atrophy and malabsorption, not structural complications like strictures.
**Option C (Whipple’s disease):** A rare bacterial infection causing malabsorption and systemic symptoms, but not ileal strictures or fistulas.
**Clinical Pearl / High-Yield Fact**
Crohn’s disease is the **only IBD** associated with **fistulas** and **skip lesions** (non-contiguous areas of inflammation). Ulcerative colitis is limited to the **colon** and presents with **continuous mucosal ulceration**. Remember: *“Crohn’s is a transmural, penetrating, fistulating disease—UC is a mucosal, continuous, cancer-risking disease.”