Ultrasound is a reliable first‐line imaging modality for the assessment of patients with gynaecological concerns. In patients with suspected endometriosis, ultrasound serves three purposes. First, it is used to evaluate the aetiology of the patient’s symptoms. Second, it has the potential to map the disease location. Lastly, it can ascertain the extent of disease.

From a clinical perspective, these products of ultrasound may benefit patients by ensuring a thorough understanding of disease by both the patient, who needs to provide informed consent to treatment options, and the physician, who may adequately prepare for potentially advanced surgical procedures. In many cases, when deep endometriosis (DE) exists, physicians need to consider referral to an appropriate gynecologic surgeon with advanced skill. The multidisciplinary input of other specialists such as colorectal or urologic surgeons or fertility specialist may also be necessary.

Recently, the International Deep Endometriosis Analysis (IDEA) group published a systematic approach to sonographically evaluate the pelvis in patients with suspected endometriosis. This consensus statement was developed to standardise anatomical landmarks, nomenclature of disease and the components of an ultrasound seeking to identify DE. A four‐step system was introduced, including routine evaluation of the uterus and adnexa, evaluation of soft markers such as site‐specific tenderness (SST), assessment of the pouch of Douglas (POD) using the ‘sliding sign’ and, finally, assessing the presence of DE nodules compartmentally throughout the pelvis