A<unk>  is usually a sac formed by the lining of the abdominal cavity (peritoneum). The sac comes through a hole or weak area in the fascia, the strong layer of the abdominal wall that surrounds the muscle.
The types of<unk> s are based on where they occur:
Femoral<unk>  appears as a bulge in the upper thigh. This type is more common in women than men.
Hiatal<unk>  occurs in the upper part of the stomach.
Incisional<unk>  can occur through a scar if you have had abdominal surgery in the past.
Inguinal<unk>  appears as a bulge in the groin. This type is more common in men than women. The bulge may go all the way down into the scrotum.
Umbilical<unk>  appears as a bulge around the belly button. It occurs when the muscle around the navel doesn't close completely.
Hernia
Abscess
Adhesion 
Volvulus
Wound dehiscence
Thrombus
Transistasis
Internal bleeding