The authors report a rare case of stenotic sigmoid endometriosis which presented with constipation and dysmenorrhea in a 48-year-old woman without past gynecological history. There were no typical radiological and endoscopic findings and only pathological examination revealed endometriosis. The patient did well after sigmoid resection and bilateral salpingo-oophorectomy and has had no further complaints. The authors stress the rare location of the disease and review the literature about etiopathogenetic hypotheses and pathological features. The diagnostic value of clinical examination, barium enema and colonoscopy is low as endometriosis rarely involves the mucosa. This case led the authors to discuss about diagnostic difficulties, differential diagnosis and therapeutic options.