Intestinal Obstruction

Intestinal obstruction may be mechanical or non mechanical

• Mechanical obstruction may be adhesions, hernias, diverticulitis, carcinoma, regional enteritis, gall stone obstruction, intussusception.
• Non-mechanical may be neuromuscular distur­bances leading to ileus.
• Obstruction may occur in small intestine or large in­testine.
• Small intestine obstructions are due to adhesions and hernias.
• Large intestine or colonic obstruction is due to car­cinoma, diverticulitis, volvulus.
• Pseudo-obstruction is a motility disorder without mechanical obstruction.
• Adynamic ileus (atonic or paralytic ileus) is the most common cause of obstruction.
• It is due to peritoneal injury with hydrochloric acid, colonic contents, pancreatic enzymes, blood and urine.
• Retroperitoneal causes of adynamic ileus are ret­roperitoneal hematoma, ureteral calculus, pyelone­phritis.
• Dynamic ileus or spastic ileus is uncommon ant!- is due to heavy metal poisoning, uremia, porphyria, in­testinal ulcerations.

Pathophysiology

• Obstruction gives rise to increased intra luminal pres­sure.
• Accumulation of gas and fluid occurs in the obstructed segment.
• There is impairment of blood supply. Bacterial invasion occurs.
• Peritonitis may occur.
• Ventilation becomes restricted due to elevation of dia­phragm and distention of abdomen.
• There may be atelectasis of lung (collapse of lung). Venous return is hampered.
• There is loss of fluid and electrolytes.
• There is hypokalemia, and dehydration because of vomitings.
• There is hemoconcentration, hypovolaemia, renal fail­ure.
• All this can lead to shock and death.

Symptoms of Intestinal Obstruction

• · Mid-abdominal pain
• · Paraoxysmal pain, cramps, colics
• · Audible borborygmi
• · In strangulation, pain is localized
• · There is vomiting of bile and mucus
• · Low ileal obstruction gives rise to feculent vomitus, very foul smelling
• · Hiccups or singultus
• · Obstipation (gas)
• · Diarrhea due to partial obstruction
• · Blood in the stool in intussusception
• · Altered bowel habit
• · Constipation.

Physical findings

• · Abdominal distension, more in colonic obstruction ‘
• · Tenderness, rigidity
• · Fever more than 100°F
• · Shock in strangulation
• · Rigidity, tenderness, fever in peritonitis
• · Hernias
• · Palpable mass
• · Loud high-pitched borborygmi.

Lab findings

• · Leucocytosis
• · Increased serum amylase.

X-ray

• Shows distended and gas filled loops of small intes­tine in step-ladder pattern with air fluid levels and no colonic gas shadows.
• In strangulation, coffee-bean shaped mass seen. In adynamic ileus, colonic distension seen.

Sigmoidoscopy

• It shows volvulus and other diseases.

Barium study

• Barium study may be done by mouth for obstruction in small intestine. Oral barium should never be given in colonic obstruction.

Treatment of Intestinal Obstruction

• In obstruction, always operative treatment is the best choice.
• For strangulation – urgent surgery. Conservative management in incomplete ob­struction and in complete obstruction, along with surgery.
• IV fluids, IV potassium, nasogastric tube for suc­tion, antibiotics, and sometimes neostigmine in colonic ileus.
• The degree of volume depletion and metabolic derangement
• The severity, cause, extent and location of the obstruction
• Whether nonoperative management can be considered
• The need for and timing of operative intervention