Differentials

Ileus

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Less cramping abdominal pain; often associated with another cause (e.g., postoperative, systemic infection, medications).

INVESTIGATIONS

CT scan shows passage of contrast throughout the small bowel and into the rectum.

Infectious gastroenteritis

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Vomiting, typically nonbilious. Diarrhoea.

INVESTIGATIONS

Abdominal CT scan will be negative for any intestinal obstruction; stool cultures may be positive for viruses or bacteria.

Large bowel obstruction

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Very distended abdomen; constipation progressing to absolute constipation.

INVESTIGATIONS

CT will reveal the level of obstruction in the bowel.

Intestinal pseudo-obstruction

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Chronic condition; constipation; often associated with administration of neurological medications (e.g., amitriptyline, imipramine). Rarely, clozapine has been associated with pseudo-obstruction.[39]

INVESTIGATIONS

X-ray and CT may show dilated small or large bowel, which may be massively dilated.

Acute appendicitis

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Pain in right lower quadrant with nausea; vomiting (nonbilious).

INVESTIGATIONS

Ultrasound and CT may confirm diagnosis in most cases.

Acute pancreatitis

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Continuous upper abdominal pain radiating through to the back; nonbilious vomiting.

INVESTIGATIONS

Increased amylase and lipase; CT scan shows inflamed pancreas.

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