Hi, thanks for using health care magic
There is a condition called infected urachal cyst
which can sometimes present with abdominal pain
, fever and vomiting.
There is a connection between the bladder and umbilicus
which is normally closed off after birth, in some persons it closes off incompletely and a cyst develops. This cyst can become infected.
It is normally treated by incision and drainage
of the area.
Hope this helps,