Case 47

62 year old M presents with one day of moderate throbbing abdominal pain and increasing distension. He denies vomiting but is nauseous. He denies fever, chills, diarrhea. He is s/p cholecystectomy and has a history of Crohns disease.

VITAL SIGNS: T: 96.8F, HR: 109, RR: 18, BP: 141/95, SpO2: 98% RA.

CONSTITUTIONAL: Well-developed; well-nourished; in no acute distress.
SKIN: Warm and dry, no acute rash.
HEAD: Normocephalic; atraumatic.
EYES: PERRL, EOM intact; conjunctiva and sclera clear.
NECK: Supple; non tender.
CARD: S1, S2 normal; no murmurs, gallops, or rubs appreciated. Regular rate and rhythm.
RESP: No wheezes, rales or rhonchi.
ABD: Hypoactive bowel sounds present; tense; distended; tender to palpation in all quadrants
EXT: Normal ROM. No clubbing, cyanosis or edema.
LYMPH: No acute cervical adenopathy.
NEURO: Alert, oriented, grossly unremarkable
PSYCH: Cooperative, appropriate.




  1. What pathology do these images depict?
  2. What frequency probe is used and why?
  3. What sonographic signs lead to diagnosis?
  4. What are some common causes of this condition?
  5. What is the definitive management?


  1. SBO
  2. The best probe is this highest frequency probe that can be used based upon the patient’s body habitus.  The linear probe is ideal for this study as the higher frequency allows higher resolution images of superficial structures and in many cases directly visualize the intestinal contents.  However, often the curvilinear probe needs to be used in a pateint with a larger body habitus.
  3. When evaluating for SBO the operator should be looking for fluid filled loops of bowel measuring greater than 25mm in diameter.  The bowel wall is usually <3mm, but may be thickened in SBO.  An experienced operator may be able to visualize the transition point but bowel gas and patient habitus can make this difficult in practice.
    • Video47a: The “Piano key sign” is fingerlike projections from the bowel wall which represent plicae circularis and indicate edema of the wall.
    • Video 47b: The “Tanga sign” is a anechoic area overlying the hyperechoic wall and is indicative of fluid surrounding the bowel wall.
    • Video 47c: You should also see bi-directional peristalsis, often described as intestinal contents moving in a “to and fro” or “whirling motion”.
  4. Many patients with SBO will have something concerning in their history. Prior SBO, abdominal surgery, autoimmune or inflammatory bowel disease all increase the risk of developing adhesions which lead to obstruction. Incarcerated or strangulated hernia and mass effect from malignancy can also cause SBO.
  5. NG tube decompression is first line treatment as well as making the patient NPO. These patients are admitted to surgery and observed, if the obstruction does not resolve on its own they require surgery to remove the obstruction.