Patients and their doctors are calling for better care for a hidden but debilitating condition that hits young people and extremely hard.
Almost 21,000 New Zealanders have Inflammatory Bowel Disease (IBD) - better known as Crohn's disease and ulcerative colitis - a fifth of them children, according to a new study.
Young adults in particular are affected with onset occurring typically between the ages of 15 and 35.
The report says this country has one of the highest rates of IBD in the world, costing $245 million a year.
The study, done for the Crohn's and Colitis New Zealand patient group by economist Suzanne Snively and others, says the conditions are chronic, lifelong and currently incurable.
The relapsing and chronic nature of IBD "has broad and often profound impacts on a person's physical and psychological wellbeing, through ongoing debilitating symptoms, social stigma, the reduction in ability to work, the management of bathroom access issues, difficulty with physical intimacy and other aspects, it says.
Symptoms include abdominal pain, diarrhoea, rectal bleeding and weight loss - reasons why patients tend to keep it to themselves. The cause is not yet known, but the study says it's an emerging global disease.
Behind much of the high and rising annual cost is new biologic drugs, notably infliximab and adalimumab, which are reserved for the most serious patients who have failed to respond to other treatments. Adalimumab, funded for 1114 patients last year, cost $19m in 2016 in total.
Strict requirements governing access to top-end drugs meant many patients who could benefit from receiving them early may not qualify.
As well, the study said feedback from patients and clinicians indicated inequities in treatment.
"There is an apparent strong correlation between access to pharmaceutical therapies and the number of gastroenterologists in the [DHB] region. Patients in areas without gastroenterology specialists tend to have less access to pharmaceutical therapies."
Diagnosis could also take time, with symptoms being frequently misinterpreted and patients going undiagnosed and treated until symptoms became more severe. Crohn's and Colitis New Zealand founder and co-chair Brian Poole said 60 percent of patients are diagnosed in A&E [hospital Accident and Emergency departments] with out-of-control pain and inflammation.
The study concludes the current model of care for patients is inadequate, inconsistent and inequitable. It also calls for a national IBD registry so the prevalence and incidence is clear for each district health board.