Urinary stones are one of the most common diseases of the urology. Its treatments are both surgical and medicinal. Tamsulosin is the most commonly used alpha-blocker, which has a proven role in increasing the rate of expulsion, as well as decreasing expulsion time. Recently, phosphodiesterase inhibitors such as tadalafil have been considered in the treatment of urinary stones. In this randomized, double blind clinical trial, 132 patients with lower ureteral stones, aged 18 to 65 years old, and having a single distal ureteral stone, smaller than 10 mm, will be included. Patients with GFR <30; single kidney; multiple ureteral stones; history of open or endoscopic surgery in the urinary tract and diabetes will be excluded. First, all patients will undergo physical examination, and laboratory and imaging (CT scans without contrast) will be requested. Patients will be randomly divided into three groups by random allocation, treated with: tamsulosin 0.4mg daily (group 1), tadalafil 10mg daily (group 2), and placebo (group 3). All patients with renal colic will receive diclofenac 100mg oral or suppository, and in the absence of improvement, 50mg intravenous pethidine will be prescribed. If there is a resistant colic, an emergency treatment intervention will be taken. A filter or cloth for urine filtering will be used by patients to diagnose stone expulsion. Patients will be monitored for every 2 weeks (up to a maximum of 4 weeks) until stone expulsion.