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.
It is well accepted in the literature that GERD is caused by an increase in intra-abdominal pressure (IAP). Acid reflux occurs when pressure causes gastric distention (stomach bloating) that pushes the stomach contents, including acid, through the LES into the esophagus.