<prompt> String of beads appearance on abdominal X-ray is seen inSmall bowel obstructionLarge bowel obstructionMeconium ileusGastric outlet obstruction  <response>: Ans. a Small bowel obstruction Ref. Graingers Diagnostic Radiology 4thpg. 981, 1089FeaturesSmall bowelLarge bowelHaustraAbsentPresentValvulae conniventesPresent in jejunumAbsentNumber of loopsManyFewDistribution of loopsCentralPeripheralDiameter of loopSmallLargeRadius of curvature of loop30-50 mm50 mmSolid faeces only reliable signAbsentMay be presentString of beads sign-SMALL BOWEL OBSTRUCTION Erect films show multiple fluid levels and dilated gas-filled loops of small bowel are readily identified on supine film. Dilated fluid-filled loops of small bowel may be seen as sausage shaped soft tissue densities. String of beads sign gas trapped between valvulae conniventes only when very dilated small bowel is almost completely fluid filled and it is virtually diagnostic of small bowel obstruction, step-ladder appearance in low obstruction the greater the number of dilated bowel loops, more distal is the site obstruction and the concertina effect in jejunal obstruction are known features. Singlemultiple loops of 2.5-3 cm in diameter with three air-fluid levels in erect film candy-cone appearance is a helpful feature. Enteroclysis is proving to be reliable for investigating suspected small bowel obstruction and can differentiate postoperative obstruction from ileus. Although enteroclysis is more reliable in patients with partial, incomplete and intermittent obstruction, CT is now recommended as the technique of choice for the investigation of suspected intestinal obstruction. Small intestinal obstruction is differentiated from paralytic ileus on CT by demonstrating a transitional zone between dilated loops of small intestine proximal to the site of obstruction and collapsed loops of small intestine or colon distal to the site of obstruction.Educational points:X-ray appearanceDiagnosisString of beads signSmall bowel obstructionCupola signPneumoperitoneumRiglers double wall signPneumoperitoneumFootball signPneumoperitoneumCoffee bean signSigmoid volvulus and Strangulated bowel obstructionPseudobilroth appearanceCrohns diseaseBird of pre signSigmoid volvulusCoiled-spring appearanceIntussusceptionClaw signIntussusceptionSaw-toothed appearanceDiverticulosisHat signColonic polypApple core appearanceCarcinoma colonThumb-print signIschemic colitisReverse 3 sign of FrostburgCarcinoma head of pancreasMoulage signMalabsorption Celiac diseaseString sign of KantorCrohns diseaseString sign Ba MealCHPSBulls eye lesionLeiomyoma GIST Liver candidiasis USGMucosal granularityEarliest sign of ulcerative colitis on Ba enema 