A 53-year-old woman developed three chronic draining sinuses after Roux-en-Y gastric bypass; these persisted for almost 1 year despite antibiotics and local wound care. At approximately 1 year post-operatively, the drainage from the most superior sinus increased significantly and assumed a greenish hue, prompting concerns for gastrocutaneous fistula despite negative radiologic evaluation. At surgery, the patient was found to have a retained permanent multifilament suture at the base of each sinus, with associated inflammatory and fibrous tissue and a "slimy" matrix. Confocal laser scanning microscopy of both the explanted sutures and investing soft tissue revealed extensive bacterial biofilm formation. Also at surgery, a frank fistulous track was noted communicating the most superior suture/sinus to the gastric remnant, necessitating laparotomy and remnant gastrectomy in addition to removal of the foreign bodies (sutures) and concomitant panniculectomy. The patient has subsequently been free of complaint or finding for over 3 years.