History and exam

Key diagnostic factors

common

abdominal pain

Often described as crampy and intermittent; can be severe. May be accompanied by vomiting, and often precedes the onset of vomiting.

constipation/failure to pass flatus or stool

Due to distal interruption of fecal flow. Constipation is not always absolute. Some patients may still pass flatus and small amounts of stool especially early in the course.[27]

vomiting

May be bilious; occurs after onset of pain.

abdominal distention

A common finding in patients with SBO. May be less prominent with more proximal obstructions. It is classically associated with high-pitched, increased frequency bowel sounds; however, the accuracy of abdominal auscultation for bowel obstruction has been questioned.[18]

abdominal tenderness

Moderate to severe tenderness may be associated with intestinal ischemia; a sign of progressive disease and impending tissue necrosis.

peritonitis

In the setting of intestinal ischemia, necrosis, and/or perforation.

presence of risk factors

There may be evidence of risk factors for SBO including manifestations of Crohn disease, presence of a hernia, or evidence of previous surgery (e.g., surgical scars).

uncommon

palpable abdominal mass

A mass may be palpated in the abdomen, suggestive of an underlying malignancy as the cause of the SBO.

Other diagnostic factors

common

nausea

This is an early event in the setting of either partial or complete SBO.

fever

Nonspecific inflammatory response to the presence of obstruction. In cases of simple SBO, fever may be present, but is likely to be mild. In complicated SBO, patients report fever with rigors.

tachycardia

Reflective of dehydration and pain.

tachypnea

Reflective of dehydration and pain.

severe lethargy

Present in complicated SBO or patients with severe dehydration.

hypotension

May be present in advanced stages of complicated SBO.

uncommon

diarrhea

In acute SBO, there can be hyperperistalsis distal to the obstruction, leading to diarrhea.

groin swelling

May be due to the presence of incarcerated and/or strangulated hernias in the groin.

Use of this content is subject to our disclaimer