People suffering from Omphalophobia are terrified of belly buttons- their own or, in some cases, those of the others. They do not like touching their navel (or even other people touching it). Sometimes the mere sight of the belly button is enough to make them feel disgusted or terrified.
Gaze deep into the darkness of the hole, and be afraid!
Those with this phobia are typically terrified of both touching and even looking at a bellybutton.
Even more horrific for them, would be having their own bellybutton touched.
I myself flinch a little when either I or someone else pokes around there, but only because my navel area is pretty sensitive for some reason. It doesn’t scare me.