Scalloping of edge of sigmoid colon on barium enema is seen in:
**Core Concept**
Scalloping of the edge of the sigmoid colon on barium enema is a radiological finding indicative of the presence of diverticula. Diverticula are outpouchings of the colonic wall, which occur due to increased pressure and decreased compliance of the colonic wall. This increased pressure can lead to herniation of the mucosa and submucosa through the weakest points in the colonic wall.
**Why the Correct Answer is Right**
The correct answer involves the pathophysiology of diverticula formation. As the intraluminal pressure increases, the colonic wall becomes stretched, and the mucosa and submucosa herniate through the weakest points, creating diverticula. This process can lead to the scalloping appearance on barium enema due to the outpouchings of the colonic wall. The sigmoid colon is a common site for diverticula formation due to its narrower diameter and more rapid transit of contents.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the radiological finding of scalloping of the edge of the sigmoid colon.
**Option B:** This option is incorrect as it does not directly relate to the pathophysiology of diverticula formation.
**Option C:** This option is incorrect as it is not a characteristic feature of diverticula.
**Clinical Pearl / High-Yield Fact**
A classic radiological sign of diverticulosis is the presence of multiple small outpouchings along the colonic wall, which can give a "cork screw" or "beaded" appearance on barium enema.
**Correct Answer:** A. Diverticulosis