When performing plain films for bowel obstruction, which of the following findings may be visible?

The presence of dilated loops of bowel is a classic radiographic finding in cases of bowel obstruction. When an obstruction occurs, gas and fluids accumulate proximal to the obstruction site, leading to distension of the bowel. As the obstruction prevents normal passage, the dilated sections become evident on plain abdominal films.

Radiologists will typically look for specific patterns, such as the "stacked coin" appearance or multiple air-fluid levels within these dilated loops, which further helps confirm the diagnosis of an obstruction. This finding is direct evidence of the pathology affecting the gastrointestinal tract and permits healthcare providers to manage the condition accordingly, whether through conservative management or surgical intervention.

The other findings mentioned do not correlate with bowel obstruction. For instance, air-fluid levels in the lungs would suggest pulmonary pathology rather than gastrointestinal issues. An enlarged cardiac silhouette typically indicates heart-related concerns, while circular shadowing would not be a standard finding associated with bowel obstruction and may indicate other scenarios like neoplasms or abscesses. Thus, recognizing dilated loops of bowel assists clinicians in diagnosing and treating bowel obstructions effectively.