Rectal drainage: unusual evolution of a psoas abscess.

We report two cases of primary psoas abscess in two patients of 15 months and 4 years of age. As the first case showed the natural history of this process the second one was large enough to produce a huge ureterohydronephrosis and to drain through the rectal wall to the rectum spontaneously, although this natural way did not achieve complete drainage. Both were treated by open drainage and systemic antibiotics with good response. They were discharged at the 7th and 12th postoperative day. 5 months later no complication has come up. Etiological, clinical and therapeutic aspects of this unusual pathology are reviewed.