<prompt> Mechanical bowel obstruction is differentiated from paralytic ileus in X rays byAbsence of rectal gas shadowElevated hemidiaphragmDilated bowel loopsMultiple air fluid levels  <response>: Answer: a Absence of rectal gas shadow BAILEY 26th ED, P-1189INTESTINAL OBSTRUCTIONProximal small bowelDistal small bowelLarge bowel Vomiting early and profuse Minimal distension Colicky pain Peristalsis not seen Little evidence of air fluid levels in X-ray Pain - intermittent, colicky Central distension Vomiting delayed bilious Step ladder peristalsis Multiple air fluid levels Pronounced early distension Pain is mild Vomiting faeculent and dehydration are late Right to left peristalsis may be seen Proximal colon and caecum are distended on X-rayJejunum - Concertina or ladder effect due to valvulae conniventes Herring bone patternFluid levels appear later than gas shadowThree inconstant fluid levels in adults considered normalFundus of stomachDuodenal capTerminal ileumFew fluid levels in the small intestine may be physiological in infants less than 1 yearFluid levels in non obstructive conditions Inflammatory bowel disease, Acute pancreatitis, Intraabdominal sepsisPARALYTIC ILEUSFailure of transmission of peristaltic waves secondary to neuromuscular failureIntestinal obstructionslowingabsence of passage of luminal contents without a demonstrable mechanical obstructionEtiologyPost operativeA degree of ileus usually occurs after any abdominal procedureSelf-limiting 24-72 hoursMay be prolonged in Hypoproteinemia or metabolic abnormalityIntra-abdominal inflammationperitonitis, abscess, retroperitoneal hemorrhageReflex ileus: following fractures of spineribs, retroperitoneal hemorrhage or application of a plaster jacketMetabolic electrolyte derangements uremia, hypokalemia, hyponatremia, hypo and hypomagnesemia, diabetic coma, hypoparathyroidism, hypothyroidismDrugs opiates, psychotropic agents, anticholinergic agents, calcium channel blockersIntestinal ischemia; Myocardial infarction; Ureteric colicClinical featuresAbdominal distension usually without colicky abdominal painNausea, vomiting, absent bowel sounds and absolute constipationNo passage of flatusIn the absence of gastric aspiration, effortless vomiting may occur X-Ray: gas filled small and large bowel loops with multiple air fluid levelsTreatmentNasogastric decompression, IV fluids, electrolyte managementTreat the underlying causeCatchpole regime: adrenergic blocking agent cholinergic stimulant neostigmine used in resistant casesParalytic ileusMechanical Obstruction Generalized, uniform, gaseous distension of the large and small bowel Diffuse air fluid levels Involvement of large bowel and lack of a transition point Quiet abdomen Dilated loops of small bowel proximal to the obstruction; no air in colon Step ladder airfluid levels Transition point seen Valvulae conniventes are visible in jejunum concertina or ladder effect Featureless ileum Initially active peristalsis; later quite 