One of the most interesting debates surrounding deep endometriosis concerns the management of patients with colorectal lesions and pregnancy intention, for which no strong first level of evidence data exists to recommend performing surgical excision of colorectal endometriosis or ART. Studies assessing the policy of primary IVF have recorded pregnancy rates inferior to 45% and estimated cumulative pregnancy rates after up to 3 cycles or IVF as high as 68%. Other authors have reported pregnancy rates over 60% in patients undergoing primary surgery for colorectal endometriosis, with spontaneous conception representing up to 60% of pregnancies. Although overall pregnancy rates appear roughly comparable in patients undergoing either IVF followed by surgery or surgery followed if required by IVF, questions remain as to whether delaying surgery for months or years impairs health. Delaying surgery may lead to bowel occlusion, higher rates of radical colorectal procedures, increased postoperative morbidity and prolonged painful complaints. To provide definitive answers requires a randomized trial on an international scale with a sample size exceeding 400 patients and follow up averaging 4 years.