The SUSPEND ( Spontaneous Urinary Stone Passage ENabled by Drugs ) trial is a multicentre , double-blind , randomized controlled trial evaluating two medical expulsive therapy strategies ( nifedipine or tamsulosin ) versus placebo.Patients aged @ to @ with a ureteric stone confirmed by non-contrast computed tomography of the kidney , ureter and bladder will be randomized to receive nifedipine , tamsulosin or placebo ( @ participants per arm ) for a maximum of @days .