Thanks for contacting healthcare magic... You have problem of stomach pain and nausea that may be because of food intolerance. Intestinal condition like celiac disease cause gluten foods consuption lead to this type of symptoms. Some dairy product also cause nausea and abdominal problems in lactose intolerance. Indigestion and constipation problem may cause nausea and swell abdominal area. Diverticulitis may cause stomach pain and gas problem. Consent a physician for further diagnosis. Proper history and investigation helpful for diagnosis. Abdominal ultra sonography is helpful. Barium abdominal x ray helpful for diagnosis further diagnosis. I hope my guidance helpful to you.. Take care. Thank you.