A two-year-old boy allegedly murdered by his mother likely had a perforated stomach when he died, indicating blunt trauma, a medical expert has told Wollongong Local Court.
The boy's extensive injuries were detailed on Thursday during day two of committal proceedings against the Berkeley woman, who has been committed to stand trial in the Supreme Court for her son's murder.
Paediatric surgeon Dr Hugh Martin examined photographs of the boy's injuries and determined he had contracted the potentially fatal stomach condition peritonitis, where thin tissue lining the inner wall of the gut becomes inflamed.
The condition could cause "considerable pain", loss of appetite, lethargy, diarrhoea and temperature disturbances. And in severe cases it would lead to death if untreated, the doctor told the court.
"It would be unlikely that an astute observer would not see some change in the child within eight to 10 hours [of the onset of peritonitis]," he said.
No tear was discovered in the boy's stomach to explain the condition during a post-mortem examination but Dr Martin focused on a piece of bright, golden matter - about 1-1.5cm - which he identified as escaped bile.
"It can only escape if there is a breach of the gut wall, so I'm forced to conclude this ... was due to perforation of the gut," he said.
Photographs showed bruising to the boy's stomach in two places.
Dr Martin said he believed the stomach tore as a result of blunt trauma to a vulnerable juncture.
In earlier evidence, Dr Kristina Prelog, a radiologist at the Children's Hospital at Westmead, offered likely time frames for the various fractures to the boy's body, including his upper right arm (two weeks old); right forearm and scapula (two to three weeks); a clavicle and left forearm (more than three weeks) and another bone in his left forearm ("it could be six weeks, it could be six months").
She said the different sites and ages of the injuries were "highly suggestive of non-accidental injury".
Further fractures to three of the boy's ribs supported the conclusion, particularly when coupled with the scapula fracture, the doctor said.
Magistrate Michael Stoddart committed the woman to stand trial for murder.
The matter has been adjourned to the Supreme Court in Sydney on May 2 for arraignment.
The woman remains in custody.