Thanks for using Healthcaremagic,
After going through your details, causes of distension of abdomen may be due to acid peptic disorder and dyspepsia
and meteorism which means excess of air in intestines.
Other possibilities should be considered visceral fats(Central obesity) or even collection of fluid in abdomen(Ascites
), Even a hernia?
You should consult Physician and get your examination and investigation to detect any cause, the simple one is ultrasonography
If everything is fine then it is lax abdominal muscle may give appearance of protuberant abdomen.
Please avoid constipation
take adequate amount of water and continue to follow healthy lifestyle.
Hope this helps.
Dr.Akhilesh Dubey M.D.