An 80-year-old woman with a known history of femoral hernia is admitted to the hospital because of strangulation of the hernia. There is a tender swelling in the right femoral region immediately below and lateral to the pubic tubercle. She has had multiple bowel movements without relief of symptoms. What is the most likely diagnosis?

**Core Concept**
The diagnosis of a strangulated femoral hernia requires an understanding of the anatomy of the femoral canal and the clinical presentation of hernia strangulation. A femoral hernia occurs when tissue protrudes through the femoral canal, a narrow passageway in the thigh that allows the femoral vessels to pass through.

**Why the Correct Answer is Right**
A strangulated femoral hernia occurs when the hernia becomes constricted, cutting off blood supply to the trapped tissue. This can lead to ischemia, necrosis, and potentially life-threatening complications. The patient's symptoms of a tender swelling in the right femoral region, multiple bowel movements without relief of symptoms, and a history of femoral hernia are consistent with strangulation of the hernia. The location of the swelling immediately below and lateral to the pubic tubercle is also consistent with a femoral hernia.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the clinical presentation of a strangulated femoral hernia.
**Option B:** This option is incorrect because the patient's symptoms and history are not consistent with a strangulated inguinal hernia.
**Option C:** This option is incorrect because the patient's symptoms and history are not consistent with a femoral vein thrombosis.

**Clinical Pearl / High-Yield Fact**
A femoral hernia is more common in women than men, particularly in postmenopausal women, due to the wider pelvis and increased intra-abdominal pressure.

**Correct Answer:** C. Strangulated femoral hernia.

✓ Correct Answer: D. Richter's hernia