Postoperative nerve injury or neuropathy: This could be due to the surgical procedure itself, especially if it involved areas near nerves that supply the lower limbs. The symptoms could be a result of direct nerve damage or compression during the surgery.

Musculoskeletal strain: Postoperative pain and discomfort can lead to altered gait and posture, straining the muscles in the lower back, hips, calves, and feet.
Hormonal changes: Endometriosis surgery might involve removal of the uterus or ovaries, leading to sudden hormonal changes, which could exacerbate or trigger musculoskeletal pain.
Deep Vein Thrombosis (DVT): Although less common, DVT can occur postoperatively, especially after surgeries that involve prolonged immobilization, and can cause pain in the calves and feet.

Spinal epidural hematoma: A rare but potentially catastrophic complication of surgery, which can compress the spinal cord and cause severe pain, numbness, and paralysis.
Infection (e.g., osteomyelitis, discitis): Postoperative infections can cause severe pain and have serious consequences if not promptly treated.
Pulmonary embolism: While the symptoms might not directly relate to lower limb pain, pulmonary embolism is a life-threatening condition that can occur postoperatively and should always be considered in the differential diagnosis of postoperative patients with unexplained symptoms.

Complex regional pain syndrome (CRPS): A chronic pain condition that can occur after surgery, injury, or trauma, characterized by intense burning or aching pain in the affected limb.
Neoplastic or metastatic disease: Although rare, it's essential to consider the possibility of cancer spreading to the bones or nerves, especially if the patient has a history of cancer or if the pain is unusually severe or persistent.
Vasculitis: Inflammation of the blood vessels can cause a wide range of symptoms, including pain in the limbs, but it is relatively rare and would typically be associated with other systemic symptoms.