A patient states his scrotum feels enlarged. Which diagnosis is likely?

The correct diagnosis for a patient reporting an enlarged scrotum is hydrocele. A hydrocele occurs when fluid accumulates in the scrotal sac, leading to swelling and the sensation of enlargement. This condition is typically characterized by a painless swelling, and it can result from various factors, including trauma or inflammation.

While a varicocele, which involves the enlargement of veins in the scrotum (often described as a "bag of worms" sensation), can also cause scrotal swelling, it is more specifically associated with dilated veins rather than fluid accumulation.

The other conditions mentioned, such as meningocele and rectocele, pertain to different anatomical areas and issues, and are not relevant to scrotal enlargement. Meningocele is a spinal condition, while rectocele is related to the rectum bulging into the vagina. Thus, hydrocele is the most appropriate diagnosis for the symptom of enlarged scrotum.