The Department of Health and Social Care says it's written to 157 patients who've been waiting too long for a second endoscopy appointment.
It says they were identified as medics went back through more than 300 cases - and those affected had been offered prioritised appointments before the end of August.
Minister for Health and Social Care, Kate Beecroft MHK, apologised for the delays - which she described as both concerning and disappointing.
She says the average waiting time for a routine endoscopy appointment is currently 33 weeks - which she called 'wholly unacceptable', adding it could be a risk to patient safety.
Anyone can make parking discs - but only the DOI's are legal
Douglas hotel's football sign could be worth £15k
Douglas church becomes House of Dog
Manx mums relate to Paris's school holidays feelings
Okells makes it a double at beer awards
Organisers call off 11-hour music event next weekend
Plans lodged for quayside hotel and apartments in Peel
£5,000 fundraiser launched for Buddy's surgery