The presence of dark fluid areas on ultrasound after gallstone surgery usually requires consideration of inflammation or localized fluid accumulation. 1. Inflammation: After gallstone surgery, local surgical wounds may show signs of inflammation or infection, which may lead to the presence of localized dark fluid areas on ultrasound images, which can be considered to be caused by the accumulation of inflammatory cells or local inflammation. 2. Localized fluid accumulation: after some gallstones surgery, there will be localized blood seepage from the gallbladder fossa or localized fluid accumulation, which can be considered as a postoperative complication caused by surgical stimulation of the surrounding tissues, and usually will be gradually relieved during the postoperative recovery and normal body metabolism. If there is any abnormality in ultrasound or other imaging tests after gallstone surgery, the cause of the disease should be clarified immediately and treated aggressively, and appropriate medications or other treatments should be chosen under the guidance of the doctor.