Brief Answer:
Details below.

Detailed Answer:
Hello,
Thanks for asking query on this forum,
Have gone through your details and i appreciate your concerns.

Swallowing air while you eat or drink can cause air to collect in the digestive tract.Second, as you digest food, digestive gases are formed as a result of fermentation and digestion of food which can also collect. Either method can cause flatulence pain bloating etc.The patho-physiology of gas and flatulence is complicated. Understanding gut microflora, gas production, intestinal transit, intestinal propulsion of gas, and sensory function within the GI tract are essential for understanding symptom generation.The term gut microflora or microbiota means hundreds of species of bacteria which lives in our intestinal tract.These bacterias and yeast are responsible for proper digestion and fermentation of food. Hundreds of species of bacteria and yeast re found in colon of human intestine.In the same way thousands of these species flourishes in our gut these bacteria play a vital role in digestion and absorption of food.Even minor disturbances in gut microflora can lead to significant changes in gut function, including gas production.
There are various mechanism that can be related to increased flatulence

If this microbiota is disturbed food is improperly fermented causing production of large amount of gases in gut leading to severe flatulence.Hence most common cause in most of the cases is disturbed microbiota.In old patient mobility of intestines is severely compromised leading to accumulation of large amount of gases in intestines.As persitalytic moments are week gas accumulates in intestines.Severe constipation or incomplete evacuation can also hinder the passage of gases.


-Small Intestinal Bacterial Overgrowth can be a reason of severe flatulence .
Small intestinal bacterial overgrowth (SIBO) refers to a condition in which abnormally large numbers of bacteria are present in the small intestine, and the types of bacteria in the small intestine resemble more the bacteria of the colon than the small intestines causing improper and disturbed food digestion.


Tests suggested-
Small bowel imaging and a gastric-emptying scan.


Hope i answered your query with relevant details

In case you need any other professional advice feel free to ask.
Thank you.

---