**Core Concept**
A Richter's hernia occurs when only a portion of the bowel wall, specifically a segment of the intestine, is trapped within a hernia sac, leading to compromised blood supply and potential ischemia. This condition is a type of hernia where only a part of the intestine is involved, unlike a traditional hernia where the entire circumference of the intestine is entrapped.

**Why the Correct Answer is Right**
In a Richter's hernia, the trapped segment of the intestine may not show any signs of obstruction, despite the compromised blood supply. The patient's ability to pass stool during examination at surgery is a classic finding in Richter's hernia, as the remaining unaffected segments of the intestine can still function normally. This phenomenon is due to the fact that only a portion of the intestinal wall is involved, allowing the remaining segments to maintain peristalsis and continue to function.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately describe the clinical presentation of a Richter's hernia. In a Richter's hernia, the patient may not always show signs of obstruction, and the ability to pass stool during examination at surgery is a key distinguishing feature.

**Clinical Pearl / High-Yield Fact**
A Richter's hernia is a type of hernia that can mimic other conditions, such as a reducible hernia, due to the presence of only a portion of the intestine being involved. It is essential to recognize the clinical presentation of a Richter's hernia, including the ability to pass stool during examination at surgery, to avoid misdiagnosis.

**Correct Answer: C.**