Gas and Back pain. Help me out in this!

I used to take one Razo 20 tab in the morning since 2007. I feel that my stomach is full always. Sometimes I am unable to sleep in night without releasing gas and feels very discomfort at back and waist. Sometimes I realise back pain and sometimes feels pain in abdomen. Also my motion is not clear in the morning and I used to go to toilet 3 to 4 times a day. My abdomen looks bigger and feels gas is filled inside the abdomen. Sometimes constipation problem happened. My main problem which I feel is my digestive system is not properly work , or I need to change my good habits, or Gas is generating excessive due to any reason . Sometimes I used to take Evict syrup for clear my motion and sometimes it works or sometime I fell sudden loose motion. I have also suffers some diareah problem in some interval of 1 year. Back pain, constipation , Gas and big abdomen is my main concern which I need to digonys so that I can feel better. So please help me out in this regard. Many than to you advanc.