Patients with life-threatening and painful conditions such as Crohn's disease are waiting well over two years for a hospital appointment, the Belfast Telegraph can reveal.
The current waiting time for a first outpatient appointment with a gastroenterologist in the Belfast Health and Social Care Trust is 27 months.
Antrim GP Dr Allen McCullough said: "Essentially, this is not a service.
"Personally speaking, if I am referring someone to a service and they're going to have to wait more than two years to be seen, then there is no point in referring them in the first place."
Dr McCullough became aware of the situation just before Christmas when he was contacted by an irate patient.
"I rang the hospital as his GP and was told the wait time was correct," he continued.
I was told that they are only now sending for patients who were referred in October 2013.
"If you suspect a patient has cancer then you red flag them but there is always the possibility there may be some patients who might have cancer who could be among those waiting for a routine appointment.
"It isn't just cancer though, it is patients with inflamatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis and they need to be seen as soon as possible."
Symptoms of IBD include diarrhoea, excruciating pain, weight loss, fatigue and nausea.
Patients can require surgery to remove damaged parts of the bowel and severe flare-ups can be life-threatening.
The waiting time for gastroenterology in the Belfast Trust has come to light just weeks after the Health Minister committed £40m additional funding to address soaring hospital waiting times.
In November, the Belfast Telegraph revealed that children with potentially deadly heart conditions were waiting more than a year for a first outpatient appointment.
According to most recent official figures, there were 230,625 people waiting for a first outpatient appointment at the end of September 2015.
Jo-Anne Dobson, a UUP member of the Stormont health committee, said: "Waiting times across services have been out of control for many months now, but it is utterly scandalous that patients are being forced to wait longer and longer, running into years, for essential medical appointments.
"Our health service provides a fantastic level of service, but that is once you get through the door and are in the expert hands of health professionals.
"Waiting time statistics must never mask the painful reality faced by people and their families across Northern Ireland as they are forced to wait longer and longer.
"Over the Christmas period I have been taking time to consult with a number of local patient groups and organisations and as a member of the health committee, I will be raising a number of concerns with the Health Minister when Stormont returns from recess.
"These include concerns that our five local health trusts are falling far short on their own internal targets, leading to spiralling waiting times, and sadly many local people are coming to harm as a direct result.
"The minister must also look seriously at future workforce planning across the Health Service as well as increasing funding towards domiciliary care."
The Belfast Health Trust said in a statement: "Although the current waiting time for gastroenterology is currently two years and three months, the numbers of referrals into this service have increased by approximately 40%.
"The trust has now taken a number of actions to address this, including the recruitment of two consultants to increase the outpatient capacity. It is expected that these positions will be in place by the end of March 2016.
"We are also validating the current waiting list by the consultant body and will have an independent contract in place which will allow for 2,000 outpatients to be seen within a three month period from January 2016 to March 2016 with treatment carried through into 2016/17.
"This will significantly reduce the waiting time within gastroenterology."
For more information contact Crohn's and Colitis UK