Intestinal Obstruction( Definition, Types ,Complications )

 intestinal obstruction

Definition :

Intestinal obstruction occurs when the passage of intestinal contents through the lumen is impaired or it is an interruption in the normal flow of intestinal contents along the intestinal tract.

Types (causes) of Intestinal Obstruction:

1. Mechanical obstruction.

2. Paralytic (adynamic, neurogenic) ileus.

3. Strangulation obstruction.

👉  Mechanical obstruction

•  An intraluminal obstruction or a physical block to passage of intestinal contents without disturbing blood supply of bowel.

•  High small-bowel (jejunal) or low small-bowel (ileal) obstruction occurs four times more frequently than colonic.

      *Mechanical causes of intestinal obstruction:

• Adhesions from surgery, up to 70% of small bowel obstructions are caused by adhesions.

• Intussusception (telescoping of intestinal wall into itself)   volvulus (twisted loop of intestine). 

•  Hernia  

•  Tumor 

•  Stenosis , stricture

👉  Paralytic (adynamic, neurogenic) ileus

•  Peristalsis is ineffective (diminished motor activity perhaps because of toxic or traumatic disturbance of the autonomic nervous system).

•  There is no physical obstruction and no interrupted blood supply.   Disappears spontaneously after 2 to 3 days.

• Causes include:

1.   Spinal cord injuries; vertebral fractures.
2.   Postoperatively after any abdominal surgery.
3.   Peritonitis, pneumonia.
4.   Wound dehiscence (breakdown).
5.   GI tract surgery.

👉  Strangulation Obstruction

•  It compromises blood supply, leading to gangrene of the intestinal wall.  

•  Caused by prolonged mechanical obstruction.

Tests and Diagnosis of Intestinal Obstruction:

•  Physical exam.
•  Fecal material aspiration from NG tube  
•  Abdominal and chest X-rays:

1.   May show presence and location of small or large intestinal distention, gas or fluid.
2.   Bird beak lesion in colonic volvulus.  
3.  Foreign body visualization.

• Contrast Studies:

1.  Barium enema may diagnose colon obstruction or intussusception.
2.  Ileus may be identified by oral barium or Gastrografin.

•  Laboratory Tests:

1.  May show decreased sodium, potassium, and chloride levels due to vomiting.   Elevated WBC counts due to inflammation; marked increase with necrosis, strangulation, or peritonitis.
2.  Serum amylase may be elevated from irritation of the pancreas by the bowel loop.
3.  Flexible sigmoidoscopy or colonoscopy may identify the source of the obstruction such as tumor or stricture.

Complications :

• Dehydration due to loss of water, sodium, and chloride.

• Peritonitis.

• Shock due to loss of electrolytes and dehydration. Death due to shock.