**Core Concept**
Peutz-Jeghers syndrome is a rare genetic disorder characterized by the presence of hamartomatous gastrointestinal polyps and an increased risk of various cancers. The polyps in Peutz-Jeghers syndrome are most commonly found in the small intestine, particularly in the jejunum and ileum.

**Why the Correct Answer is Right**
The correct answer is due to the anatomic distribution of the polyps in Peutz-Jeghers syndrome. The small intestine, especially the jejunum and ileum, is the most common location for these hamartomatous polyps. This is because the polyps arise from the intestinal crypts, which are more abundant in the small intestine. The presence of these polyps can lead to various gastrointestinal symptoms, including abdominal pain, bleeding, and intussusception.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while the colon is a common site for various types of polyps, it is not the most common location for Peutz-Jeghers polyps.
**Option B:** This option is incorrect because the stomach is not a typical location for Peutz-Jeghers polyps, although it can be involved in rare cases.
**Option C:** This option is incorrect because the rectum is not a common site for Peutz-Jeghers polyps, which are more often found in the small intestine.

**Clinical Pearl / High-Yield Fact**
A key feature of Peutz-Jeghers syndrome is the presence of characteristic mucocutaneous melanin deposits, which can be found on the lips, oral mucosa, and digits. These deposits are a result of the same genetic mutation that leads to the development of the hamartomatous polyps.

**Correct Answer: C. Small intestine**