What Causes Severe Bloating Of Abdomen?

Hello. I am 38 years old and have 2 teenage daughters. I have had health problem since I was 8 years old. I have had endometriosis, interecystitis, chronic back pain, depression, anxiety, copd, hiatal hernia, insomnia, migraines, chest pain, GERD, acid reflux, severe scar tissue in lower abdomen and diverticulosis. For the past 4 years my belly swells really bad and i have 5 different doctors and the can t seem to find out what could be causing it. They have done all kinds tests and still can t find anything. I swell like I am 9 months pregnant with twins. DO you have any suggestions on what it could be? Please I am begging for help with this!!