Paediatric Imaging

Gastroenteritis

infection of the stomach and bowel by bacteria, viruses or parasites. Clinical presentation is with vomiting, diarrhoea and abdominal pain. The most common bacteria are Salmonella, Shigella, Escherichia Coli and Yersinia, Enterobacter and Campylobacter and, in endemic areas, Vibrio cholerae.

Gastroenteritis cause by E. Coli 0157:117 is associated with haemolytic uraemic syndrome. Viral gastroenteritis is most commonly caused by rotavirus. Clinically, the diarrhoea may be preceded by severe abdominal pain and peritonism, mimicking an acute abdomen. Bloody stools may cause further confusion as this mimics intussusception. Dehydration is a major cause of morbidity and, where severe, can cause portal vein thrombosis, renal failure and even death.

Radiological investigation is not indicated in a typical case. When the diagnosis is in doubt, plain radiographs and abdominal ultrasound are often requested. The radiographic appearances are variable and mimic bowel obstruction or ileus (see adynamic ileus). The fluid levels tend to be long as opposed to the ladder pattern of bowel obstruction. The abdomen may be gassy or relatively gasless. In general, air is present throughout the bowel. At ultrasound, some free peritoneal fluid is common. Bowel peristalsis reflects the clinical signs - active peristalsis during the phase of diarrhoea, but if ileus dominates, there is very little peristalsis. Large lymph nodes may be seen in infection with Yersinia.

HC