Industrial action by doctors at West Suffolk Hospital today will cause disruption to operations, outpatient clinics and ultrasound scans.
Members of the British Medical Association (BMA) are refusing to treat all but urgent cases following a dispute over changes to the NHS pension scheme.
The patients effected by the postponement of 11 operations, 13 outpatient clinics and seven ultrasound scans have been contacted by the hospital.
A spokesman for West Suffolk Hospital said: “We have contingency plans in place to ensure that we can continue to provide safe services for our patients during periods of industrial action.
“We have been meeting regularly with the BMA so that we can keep any disruption to a minimum, and have agreed that doctors will provide emergency and urgent care as normal.
“Anyone who is due to come to the hospital on Thursday and has not heard from us should attend as normal.”