First, when hold gas in, it will eventually come back out. "The external anal sphincter is the only part of the digestive process we have conscious control over. So, if we decide the time is not right to pass gas, we constrict the sphincter and the fart is trapped. Without a backdoor to escape from, the gases recede back into the colon. But primarily, the body is trying to push gas out. So farts that are ignored during the day are mostly released during bathroom breaks or as the body relaxes in sleep at night."
What causes that anally-expelled gas to smell? There are many variables that affect this including that person's intestinal microbiota. One major culprit is "Sulfur-rich foods include legumes (such as lentils, beans and peas) and brassicas (such as broccoli and cabbage). These fibrous veggies also contain insoluble carbs that bacteria in the colon may convert into stinky gas."
https://www.livescience.com/health/what-happens-when-you-hold-in-a-fart
What happens when you hold in a fart?
News
By Sierra Bouchér published 9/28/24
What causes that anally-expelled gas to smell? There are many variables that affect this including that person's intestinal microbiota. One major culprit is "Sulfur-rich foods include legumes (such as lentils, beans and peas) and brassicas (such as broccoli and cabbage). These fibrous veggies also contain insoluble carbs that bacteria in the colon may convert into stinky gas."
https://www.livescience.com/health/what-happens-when-you-hold-in-a-fart
What happens when you hold in a fart?
News
By Sierra Bouchér published 9/28/24
We all hold in farts from time to time, but where does the gas go?.