Hi! Good morning. I am Dr Shareef answering your query. Yes the past traumas could be responsible for your swelling by the way of causing a hematoma(collection of blood) which might have got organised. Another possibility is your history of hernia, which might be coming up on increasing intra-abdominal pressure and subsiding again on the release of pressure. However, the swelling needs to be examined by a general surgeon clinically to arrive at a diagnosis along with your other investigation reports. Therefore, I would suggest you to take appointment with a general surgeon in your area, and seek his advice on the management. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic to clear doubts on your health problems. Wishing you an early recovery. Dr Shareef