Objective: To investigate the role of sexual intercourse on passage of distal ureteral stones.

Design: Prospective, randomized controlled study.

Participants: 90 male patients with distal ureteral stones <6 mm in size undergoing a trial of spontaneous passage.

Methods: Group 1 was randomized to sexual intercourse 3 to 4 times a week, group 2 received tamsulosin 0.4 mg/day for medical expulsive therapy, and group 3 served as a control. Expulsion rate was compared at 2 and 4 weeks.

Results: Mean stone size was similar between all groups at just under 5 mm (group 1, 4.7 mm; group 2, 5.0 mm; group 3, 4.9 mm). At 2 weeks, 83.9% (26/31) patients in the sexual intercourse group had passed stones. In comparison, 47.6% (10/21) in the tamsulosin group and 34.8% (8/23) in the control group had passed stones (P =0.001). At 4 weeks, the differences lost significance, but still showed benefit for the sexual intercourse group with 93.5% passage compared to 81.0% passage in the tamsulosin group and 78.3% passage in the control. The mean expulsion time was 10.0 days in the sexual intercourse group, 16.6 days in the tamsulosin group, and 18.0 days in the control group.

Conclusions: Sexual intercourse 3 to 4 times per week may increase the probability of spontaneous stone passage for distal ureteral stones <6 mm in size.

Reviewer’s Comments: This study led to lots of conversation given the unique and unusual approach proposed to improve spontaneous ureteral stone passage. The authors hypothesized that sexual intercourse may improve spontaneous stone passage by nitric oxide release leading to relaxation of ureteral muscles. They found that the sexual intercourse group passed their stones much faster than either the tamsulosin or control group. While intriguing, several problems exist with the study, which makes me somewhat surprised that it was published. The study is extremely underpowered based on overestimations in initial statistical planning. No compliance measures with sexual activity and/or lack of sexual activity or with taking tamsulosin as prescribed were performed. Only 6% of patients were lost to follow-up in the sexual activity group compared to 23% in the tamsulosin and control arms. If those patients were lost to follow-up because they passed their stones, then the study would have no significance. Last, sexual activity would be a very brief exposure of nitric oxide to the ureter (if the theory is correct). Younger patients should still get nocturnal erections, which would also release nitric oxide for brief periods. It seems that a more consistent delivery of nitric oxide such as with PDE5 inhibitors may be more successful, and PDE5 inhibitors have shown some promise in early studies. Overall, the study makes a good headline and interesting discussion, but much better studies are needed to find a relevant method to facilitate stone passage.(Reviewer–David A. Duchene, MD).