Peritonitis is defined as inflammation of the peritoneum. The inflammatory response involves vasodilation, exudation of protein-rich fluid, cellular infiltration, pain and, chronically, formation of fibrous adhesion. The disease can be classified into primary and secondary cases.
It begins in the venous plexus along the medial side of the foot, and it runs up the medial side of the leg and knee, alongside the saphenous nerve. In the thigh, the long saphenous vein continues up the medial surface, accompanying the medial femoral cutaneous nerve.
The femoral vein runs up through the middle of both your legs, connects through at the crease of your leg and groin, and then continues up on either side of your torso area until it merges into the other larger veins leading to the heart. (So, keep in mind that there are two of these veins, one on either side of your groin area.)