Background: Large sums of money have been awarded against manufacturers of midurethral slings (MUS) because of complaints of pain and other complications, even though pelvic pain is rarely seen at the 6–12 weeks review. Hypothesis and Aims: Pain/other posterior fornix symptoms (urge, frequency, nocturia, and abnormal emptying) may appear weeks or months after MUS surgery due to dislocation of already weakened uterosacral ligaments (USL), a consequence of diversion of pelvic forces from pubourethral ligaments strengthened by the sling. Methods: Review for prevalence, pathogenic pathway from damaged USLs to pain, OAB, emptying, and other late complications by reference to data from functional anatomy imaging, mechanical support of USLs (speculum test), and post-USL surgical repair. Results: Pelvic pain and other pelvic symptoms frequently co-exist pre-operatively with SUI, but are not volunteered because patients complain of one main pelvic symptom, others being “under the surface” (Pescatori Iceberg). Late de novo occurrence of symptom complications beyond perioperative MUS surgery may occur: pain (5.7%), retention (5.4%), UTI (9.3%), and OAB (10.2%). Xray/ultrasound evidence of pelvic forces acting on USLs support the hypothesis of diversion of forces. Improvement of pain and urgency by the “speculum test” indicates USL causation, as do cure of pain and other pelvic symptoms by USL slings. Conclusions: Late-occurring PFS symptoms are the fault of neither implant, nor surgeon, but more likely consequences of pelvic forces acting on USLs already weakened by childbirth/age. Bladder/bowel/pain symptoms need to be sought out preoperatively and discussed before MUS surgery. Brief Summary: Late MUS complications, OAB, pain, retention subject to class actions, may be caused by uterosacral dislocation from pre-existing structural weakness, not surgeon or device.