Hi. Thanks for your query. Noted the history about your colon reconstruction surgery, pain in the lower side on both the areas and feeling like falling out on standing for a long time but get a relief on sitting down. The causes can be: Colitis. Ovarian problems. IBS meaning irritable bowel syndrome and so on. I would advise you the following in such a situation. Contrast enhanced CT scan is usually needed as ultrasound is not effective in finding many of the problems. Clinical evaluation by the operating surgeon is needed as he knows what exactly was done. Take only liquid diet. Visit the Er if required for X-ray of the abdomen in standing position and other tests as may be required.