There is no current consensus among biologists on the questions of how sex in Eukaryotes arose in evolution, what basic function sexual reproduction serves, and why it is maintained, given the basic two-fold cost of sex.
Excessive production of gas by bacteria is a common cause of intermittent abdominal bloating/distention. Bacteria can produce too much gas in three ways. First, the amount of gas that bacteria produce varies from individual to individual.
Abdomen distention is often accompanied with various other symptoms and signs. Distended stomachs along with the other symptoms are an aid to diagnosing the condition. The symptoms and signs that often accompany abdominal distention are: Excess burping and flatulence.