Tests
1st tests to order
CBC
Test
Low Hb and hematocrit (Hct) offers supportive evidence of bleeding, but is not diagnostic.
Leukocytosis with a left shift suggests inflammation.
Result
low Hb and Hct; leukocytosis with left shift
capsule endoscopy
Test
Often used as part of the work up for hemodynamically stable patients with occult gastrointestinal bleeding.[27] Small bowel capsule endoscopy may provide direct observation of Meckel diverticulum in adults and children.[28][29][30]
Result
double-lumen sign and visible diverticular entrance; may show ulcers
CT angiography or mesenteric angiography
Test
In patients with active bleeding or hemodynamic instability, CT angiography or mesenteric angiography is the preferred initial investigation.[27][33]
CT angiography is often performed before conventional angiography as it is faster, noninvasive, and widely accessible.[27]
Mesenteric angiography can detect hemorrhage in the range of 0.5 to 1.0 mL/min and is generally employed only to localize the bleeding; however, it can have a therapeutic role too.
Result
may show persistent omphalomesenteric artery; vascular blush at site of diverticulum on CT angiography; extravasation of contrast during inferior mesenteric arteriography
technetium-99m pertechnetate scan ("Meckel scan")
Test
The imaging test of choice when Meckel diverticulum is suspected in the setting of lower gastrointestinal bleeding in children. However, a negative exam does not exclude the possibility. Studies show a sensitivity of 0.80 (95% CI: 0.73 to 0.86) and specificity of 0.95 (95% CI: 0.86 to 0.98), with lower sensitivity in adults.[32][33]
Pertechnetate is preferentially taken up by the mucus-secreting cells of the ectopic gastric tissue in the diverticulum. If the diverticulum contains other heterotopic mucosa in the absence of gastric mucosa, the test will be negative. Active bleeding can also cause false negatives on Meckel scan.[33]
In adults, administration of pharmacologic agents, such as histamine-₂ (H₂)-receptor antagonists or pentagastrin and glucagon, enhances the accuracy of the scan.[31][39]
Result
ectopic focus or "hot spot"; enhancement of diverticulum
CT scan of the abdomen and pelvis
Test
Will allow diagnosis of Meckel diverticulum or related complications such as intussusception, diverticulitis, or bowel obstruction.
Result
blind-ending fluid-filled and/or gas-filled structure in continuity with distal ileum
ultrasound of the abdomen
Test
May be used as initial imaging, especially in children, if intussusception, diverticulitis, or bowel obstruction are suspected.
Result
intussusception: tubular mass in longitudinal views and a donut or target appearance in transverse views; inflamed Meckel diverticulum: tubular blind-ending structure with hyperechoic mucosa and submucosa, and hypoechoic muscular layer ("gut signature"), and may see connection of Meckel diverticulum to a peristaltic, normal, small-bowel loop; obstruction: dilated loops and abnormal peristalsis
Tests to consider
contrast enema
Test
Performed if intussusception is suspected.
Air or hydrostatic reduction of the intussusception in the setting of Meckel diverticulum has not been found to be useful.
Contraindicated if peritonitis, shock, perforation, or an unstable clinical condition is present.[36]
Result
filling defect or cupping in the head of the contrast media where its advance is obstructed by the intussusceptum
CT enterography
Test
Guidelines on imaging for gastrointestinal bleeding recommend cross-sectional imaging with CT enterography if capsule endoscopy is negative or contraindicated.[27] However, an uncomplicated Meckel diverticulum may be difficult to visualize with CT enterography.[27]
Result
blind-ended tubular or saccular bowel segment
double-balloon endoscopy
Test
May be considered if other investigations have failed to reveal the diagnosis.
One study comparing capsule endoscopy and double-balloon endoscopy found that double-balloon endoscopy was able to observe 64 of 74 possible Meckel diverticula.[37] Of the 26 patients who underwent both techniques, 20 of 22 Meckel diverticula detected by double-balloon endoscopy went undetected on capsule endoscopy. The 10 Meckel diverticula that were undetected by double-balloon endoscopy were subsequently found on surgery.[37]
Result
Meckel diverticulum identified
surgical exploration of the abdomen
Test
Definitive means of diagnosing Meckel diverticulum.
Result
Meckel diverticulum identified
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