Differentials
Mechanical bowel obstruction
SIGNS / SYMPTOMS
Localised pain; symptoms start acutely.[62]
INVESTIGATIONS
Shares many of the same signs and symptoms as ileus, so differentiating can be challenging. Obstructive series shows step-wise air-fluid levels and very dilated loops of small bowel.
CT scan shows a transition zone (dilated loops leading up to collapsed loops of bowel), and oral contrast does not reach distal to the point of obstruction.
Pseudo-obstruction (Ogilvie's syndrome)
Gastroenteritis
SIGNS / SYMPTOMS
History should indicate a likely gastroenteritis, along with symptoms of diarrhoea. It is generally self-limited.
A patient with no risk factors for ileus and who has diarrhoea is likely to have gastroenteritis.
INVESTIGATIONS
Clinical diagnosis. Further testing may be non-specific and unhelpful.
Pancreatitis
SIGNS / SYMPTOMS
Acute abdominal pain.
INVESTIGATIONS
Elevated lipase and amylase.
May have gallstones on right upper quadrant ultrasound.
Abdominal CT scan shows diffuse or segmental enlargement of the pancreas with irregular contour and obliteration of the peri-pancreatic fat, necrosis, or pseudocysts.
Acute cholecystitis
SIGNS / SYMPTOMS
Pain in the epigastrum and right upper quadrant of the abdomen.
INVESTIGATIONS
Distended gallbladder, thickened gallbladder wall, and presence of gallstones on right upper quadrant ultrasound.
Abdominal CT scan shows gallbladder wall inflammation; linear high density areas in peri-cholecystic fat tissue.
Bowel perforation
SIGNS / SYMPTOMS
Severe abdominal pain, fever.
INVESTIGATIONS
Abdominal x-ray demonstrates free intraperitoneal air.
A CT scan demonstrates bowel perforation.
Intra-abdominal abscess
SIGNS / SYMPTOMS
Fever, anorexia, crampy abdominal pain and tenderness.
INVESTIGATIONS
A CT scan demonstrates abscess.
Peritonitis
SIGNS / SYMPTOMS
Pain and tenderness of the abdominal wall. History and physical examination to evaluate for risk factors and elicit signs of peritonitis.
INVESTIGATIONS
A CT scan demonstrates peritonitis.
Intestinal pneumatosis
SIGNS / SYMPTOMS
Diarrhoea, bloody stools, abdominal pain.
INVESTIGATIONS
A CT scan demonstrates pneumatosis.
Use of this content is subject to our disclaimer