MCQ ---INTESTINAL OBSTRUCTION

 

Q1.true regarding small bowel obstruction

a.in supine radiograph –dilated,gas-filled small bowel loops larger than 3cm in diameter with little or no gas in the small bowel or colon distal to obstruction

b.upright or decubitus abdominal radiographs –multiple air fluid levels in the dilated small bowel

c.step ladder appearance

d.string of pearl sign

e.all

ANS.

e

Gas –filled small bowel loops above the obstruction may have horizontal orientation in the central abdomen ---and produce stepladder pattern .

Small amount of gas trapped between small bowel folds on upright or decubitus radiographs may appear as tiny bubbles of gas lined up along the non-dependant bowel surface ( known as string of pearls sign ) .

Gaseless  abdomen –when patients swallow little or no air ,abdominal radiographs may reveal multiple tubular soft tissue densities representing fluid-filled loops of small bowel and a paucity of bowel gas distal to obstruction producing so-called gasless abdomen.

Q2 .The most common cause of small bowel obstruction is

a.external hernia

b.post-operative adhesion

c.small bowel tumour

d.intestinal parasites

e.acute appendicitis

ANS

.b

The second most common cause of small bowel obstruction is external herna ( inguinal .femoral ,umbilical or incisional )

Q3.  All true regarding colonic obstruction except

a.more than 50% due to annular carcinoma

b.the most common site is ascending colon 

c.paucity of gas in distal colon and rectum

d.can mimic small intestinal obstruction in case of incompetent ileo-caecal valve

e.dilated gas filled loops of colon proximal to obstruction

ANS.

b

The most common site of colonic obstruction is sigmoid colon where the colon has narrower caliber .Carcinoma of the cecum and ascending colon are less likely to cause obstruction because of wider caliber of the right side of colon .

Q3.all true about closed loop obstruction except

a.segment of bowel obstructed at two points

b.usually involve large intestine  intestine

c.caused by adhesion ,internal henia or volvulus

d.coffee bean appearance

e.pseudotumour appearance

ANS.

b

Closed loop obstruction usually involve small segments .Occasionally ,there may be disproportionately dilated gas –filled loop of small bowel that has the appearance of a coffee beans .

Of obstructed segments fills with fluid ,rounded soft tissue mass produces pseudotumour  appearance .