Brief Answer:
Depleted gut flora.

Detailed Answer:
Hello,
Thanks for query.

The pathophysiology of gas and bloating is complicated.
The term gut microflora or microbiota means hundeds of species of bacteria which lives in our intestinal tract.These bacterias and yeast are responsible for proper digestion and fermentation of food. Hundereds of species of bacteria and yeast are found in colon of human intestine.In the same way thousands of these species florishes in our gut these bacteria play a vital role in digestuio 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 gas.Hence most commmon cause in most of the cases is disturbed microbiota.In old patient mobility of intestines is severly compromised leading to accumulation of large amount of gases in intestines.As persitaltic moments are week gas accumulates in intestines.Severe constipation or incomplete evacuation can also hinder the passage of gases.

Take VSL3 twice daily.
Take a proton pump inhibitor like Esomeprazole 40 mg twice daily along with a prokinetic drug (eg.Domperidone) for 7 days. This will provide you symptomatic relief from symptoms.
Apart from this, some dietary restrictions are to be followed-

- Avoid alcohol or smoking.
- No aerated beverages.
- Take light non spicy easily digestible food for few days.
- No Fast food like pizza or burger should be taken.
- Drink a cup of cold curd daily.
- Avoid fatty foods.

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