The presence of obsessions or compulsions, or both, are what distinguishes obsessive-compulsive disorder from other conditions. The obsessions or compulsions cause marked distress, are time-consuming, and interfere with a person's normal functioning.
(1989) concluded that everyone excretes stinky compounds in their urine after eating asparagus, and the only variation is in ability to smell them. Other papers using chemical tests and carefully controlled smelling tests show that there is variation in excretion of sulfur compounds in urine after eating asparagus.
It is believed that both the generation of the odoriferous urine and the ability to smell it are based on genetics. Only those with a certain gene can break down the chemicals inside the asparagus into their smelly components, and only those with the proper gene can smell the results of that chemical breakdown.