A group representing psychiatrists says careful monitoring of those who are prescribed a key anti-psychotic medicine is needed.
New Zealand-led research published this week says clozapine, which is used by 4300 people in this country for conditions including schizophrenia, can lead to constipation and, occasionally, complete bowel obstruction.
The researchers at Otago University's Wellington campus say bowel obstruction has contributed to the death of four people in the past 20 years, and put 11 others at serious risk.
They say regular prescribing of laxatives when people are put on the drug would safeguard against that.
But the president of the Royal Australian and New Zealand College of Psychiatrists, Malcolm Hopwood, said another way would be to monitor patients carefully from the outset and have a low threshold for introducing laxatives.