The symptoms are often due to swallowed air. This can occur if your mother breathes through her mouth. Lifestyle traits that increase the risk of intestinal gas also include talking while eating and drinking with a straw. Dietary changes can also lead to increased gas. For example drinking more milk, eating more salads or increasing the quantity of fiber eaten could cause your mother s symptoms.
Intestinal diseases can also produce the symptoms.
I would be more suspicious of this group of diseases if your mother also had diarrhea. If your mother had symptoms of vomiting or intermittent constipation with the gas attacks, I would consider the possibility of bowel obstruction. There is no obvious connection between the gastrointestinal symptoms and the end stage kidney disease that necessitated dialysis. Based on the information that you provided I doubt that there is a relationship with the thoracic aneurysm. This response is offered for your general information and should not replace the conclusions drawn from a careful and complete evaluation by your physician.