A Hernia Operation

One doctor operated on a person for a hernia. 

He opened his testis and took the balls out and kept it on the table. 

At the end of the operation he wanted to put his balls back into the pouch of testis. He searched operation theatre but could not find the balls of the patient. 

Lastly, he told nurse to get two small onions from his lunch box as he cannot keep his testis pouch empty.

After that operation he met the same patient in a garden for morning walk.

Being a good doc, he asked his patient how he is feeling now.

He said, "Doc everything is fine, life is very cool except that whenever I scratch my balls, my eyes start watering."