Thanks for your question on Health Care Magic. I can understand your concern. Fluid in the lungs can be due to varied reason. If fluid is there in the bag covering the lung its called as pleural effusion. Mostly it is due to infection in lungs. In order to find the cause for the same, the fluid has to be removed with a small needle inserted into that area and testing of that fluid is done to find out the cause. It is a simple procedure done under local anaesthesia. In your case it may be secondary to bowel obstruction which may resolve in due course. If persistent for more than a week then requires testing. Don t worry, you will be alright. Hope I have solved your query. Wish you good health. Thanks.