Adhesions, intussusception, volvulus, hernias, and tumors are some of the main causes of intestinal obstruction. Intestinal obstruction occurs when the intestinal lumen becomes narrowed or blocked, preventing the normal passage of intestinal contents. This causes gases and fluids to accumulate proximal to the obstruction. As pressure builds up in the blocked intestine, complications like distension, ischemia, necrosis, and perforation can occur if the obstruction is not resolved. Left untreated, intestinal obstruction can lead to serious complications such as dehydration, peritonitis, sepsis, and even death.

1. Pathophysiology of Intestinal Obstruction
Adhesions- loops of intestine become adherent to  SCI, vertebral fractures
areas that heal slowly or scar after abdominal surgery;  Abdominal surgery
produce kinking of an intestinal loop  Peritonitis
 Wound dehiscence
Intussusception- one part of the intestine slips into  GI tract surgery
another part located below it; intestinal lumen  Thrombosis, embolism
becomes narrowed
Volvulus- bowel twists and turns on itself; intestinal
lumen becomes obstructed. Gas and fluid accumulate
in the trapped bowel
Hernia- protrusion of intestine through a weakened
area in the abdominal muscle or wall; intestinal flow
may be completely obstructed. blood flow to the area
may be obstructed FUNCTIONAL
ADYNAMIC
NEUROGENIC
Tumor- within the intestine, extends into the intestinal
PARALYTIC ILEUS
lumen; outside the intestine, pressure on the wall of
the intestine; intestinal lumen becomes partially or
completely obstructed.
Cessation of peristalsis
MECHANICAL
OBSTRUCTION
Gases and fluids Bacterial
Borborygmi accumulate in the activity
area
Inc contractions of Distension of
proximal intestine intestine
Inc intraluminal Persistent vomiting
pressure
Severe
colicky
abdominal
pain Inc secretions into
the intestine Loss of hydrogen
ions, potassium
Compression of
veins
Metabolic alkalosis
Inc venous pressure
Dec absorption
Reynel Dan L. Galicinao BSN-IV, CCC MSU-IIT 13/07/09

2. Pathophysiology of Intestinal Obstruction
Edema of the
intestine
Dec arterial Compression of
blood supply terminal branches of
mesenteric artery
Ischemia,
Anoxia
Necrosis Perforation of necrotic Bacteria or
segments toxins leak into:
Gangrenous
intestinal wall
Peritoneal Blood
cavity supply
Dec Cessation of
bowel peristalsis Peritonitis Bacteremia
sounds Septicemia
COMPLICATIONS
 Dehydration due to loss of water,
sodium, and chloride
 Peritonitis
 Shock due to loss of electrolytes
and dehydration
 Death due to shock
Reynel Dan L. Galicinao BSN-IV, CCC MSU-IIT 13/07/09