How to differentiate mechanical obstruction from paralytic ileus?: (A) Elevation of hemi diaphragm, (B) Absence of rectal shadow, (C) Multiple air fluid levels, (D) Abdominal distension
Answer is B. Ans. (b) Absence of rectal shadowRef: Bailey and Love 26th edition, Page 1190* The important point to differentiate paralytic ileus and mechanical obstruction in X-ray is there will be absence of rectal gas shadow in mechanical obstruction.* Clinically bowel sounds will be absent in paralytic ileus with no pain.