**Core Concept**
Bariatric surgery is a group of weight loss surgical procedures performed on individuals with obesity, typically with a BMI of 40 or higher. These surgeries aim to restrict food intake, reduce hunger, or alter nutrient absorption to achieve significant weight loss.

**Why the Correct Answer is Right**
The correct answer is a type of surgery that does not directly involve weight loss or obesity treatment. Bariatric surgeries typically involve procedures like gastric bypass, sleeve gastrectomy, or adjustable gastric banding. In contrast, the correct answer is a surgery primarily performed for other indications.

**Why Each Wrong Option is Incorrect**
**Option A:** Gastric bypass surgery is a classic example of a bariatric surgery, where the stomach is reduced in size and reconnected to the small intestine, leading to weight loss.
**Option B:** Sleeve gastrectomy is another bariatric surgery where a large portion of the stomach is removed, leaving a narrow 'sleeve' or tube-like stomach, which restricts food intake.
**Option C:** Adjustable gastric banding is a bariatric surgery where an adjustable band is placed around the upper part of the stomach to create a small pouch, limiting food intake.

**Clinical Pearl / High-Yield Fact**
One classic exam trap is distinguishing bariatric surgeries from other types of weight loss surgeries or those performed for other indications. Always remember that bariatric surgeries specifically target obesity treatment.

**Correct Answer:** D.