Abdominal, Gastrointestinal, Genitourinary, and Hematologic Emergencies

1. Where This Starts: Hollow Organs vs. Solid Organs

The abdomen holds two kinds of organs, and they fail differently.

Hollow organs — the stomach, intestines, gallbladder, bladder — are tubes and sacs. When something blocks them or stretches them, the muscle in their walls squeezes against the blockage. So hollow-organ pain comes in waves: cramp, ease, cramp again. That's a kidney stone, a bowel obstruction, early appendicitis.

Solid organs — the liver, spleen, pancreas, kidneys — plus the aorta running down the back wall don't cramp. When they tear, rupture, or bleed, the pain is constant and deep, and it doesn't come and go.

So before you know a single diagnosis, the pain pattern already tells you something: wave-like points toward a hollow organ, constant and deep points toward a solid organ or bleeding.

Lining the whole abdominal cavity is the peritoneum, a thin membrane. Blood, pus, or intestinal contents loose in the abdomen irritate that lining directly, and an irritated peritoneum reacts one way: it makes the patient hold still. Any motion — a bump in the ambulance, a cough, a hand pressing in — stretches the inflamed lining and it hurts more. That's why a patient with peritonitis lies rigid, often with the knees drawn up to relax the abdominal wall, and doesn't want to move at all.

That single mechanism is the spine of this whole lesson: the quiet, still patient is often sicker than the loud one. You'll come back to it more than once.