An 18 year old man returns from a back packing trip. He has developed generalized abdominal pain, fever and vomited a couple of times.
The junior doctor is concerned he has appendicitis and asks you to perform an ultrasound.
Describe and interpret these scans
Image 1: Transverse fanning through the lower left and central abdomen.
Multiple loops of fluid filled small bowel are seen. These are actively peristalsing, the wall is not thickened (≤ 3mm), and they are not dilated (≤ 2.5- 3cm outer wall to outer wall).
Image 2: Longitudinal section of ascending colon in the right flank.
Haustra are seen clearly defined by the luminal fluid. Again the wall is not thickened and it is not dilated (≤ 6cm colon; ≤ 9cm caecum) This loop shows little peristalsis and the small amount of movement seen in the fluid component is not the to and fro movement of peristalsis against obstruction, but rather subtle movement caused by normal diaphragmatic excursion in an aperistaltic bowel segment.
Salmonella enteritidis enteritis
Like so much of ultrasound, clinical correlation is key.
Fluid filled bowel loops are a relatively non-specific finding and an ileus can be associated with many things. In this case the widespread fluid-filled, non-dilated most active bowel loops combined with the history of recent travel, a family member with salmonella enteritidis enteritis, and the vomiting and pain – even before the diarrhoea set in – made the diagnosis almost certain.