Unable to clean colon. In my colon.

Whenever i go to bathroom to empty the stomach,the stomach is not getting cleaned completely.Due to this huge gas is made after one hour of going bathroom.sometime after every 5-10 mins gas is made .AGain after 3-4 hours i have to go to bathroom to clean stomach completely.please note that i am taking healthy ,nutritious and fibrous food.so,this might not be case of constipation.I do exercise also.is this is problem of large intestine.sometimes after 1 hour of going bathroom,the gas creation is more intense compared to before going bathroom.is bacteria are more active in my colon.i am suffering from this problem from last 5 years .before this everything was fine. So,it may be noted that the main concern here is because of not cleaning of stomach completely ,gas is created.I tried several home remedies like doing some exercise or drinking water or drinking papaya shake before going to bathroom.but nine of them working. Please tell why this is happening from last 5 years and remedy.