How many times per day is it normal to fart? The question may draw a smile—but until now the answer lacked serious data. Australian researchers have designed a mobile app to measure flatulence in real time among more than 6,400 people. Their findings establish, for the first time, a scientific reference for what constitutes a healthy intestinal transit.
What you will learn
- How often the majority of people emit gas per day—and when this peak occurs
- What biologically distinguishes odorless gases from odorous ones
- Why a sudden inability to fart is more worrying than an excess
A Normal Function, But Never Truly Measured
Flatulence is one of the most universal yet least studied digestive functions in real-world conditions. It helps the digestive system keep pressure low in the gut and prevents painful distensions. Without it, the consequences would be serious.
Yet, until now, no large-scale study had measured the real frequency of flatulence in healthy individuals in their daily lives. Available data came from small groups or patients suffering from digestive disorders—a significant bias when defining what is normal.
A Mobile App to Measure the Intimate
To fill this gap, researchers at the Australian CSIRO developed an app named Chart Your Fart, available on Android and iOS. More than 6,400 Australians aged over 14 agreed to record every gas emission for at least three consecutive days.
The protocol was simple but rigorous: no recent major dietary changes, and real-time recording to avoid memory bias. The results are published in JAMA Network Open.
Five Times a Day, with a Peak in the Evening
The majority of participants—nearly 80%—reported emitting gas between two and seven times per day. The overall average stood at five emissions daily, with a slight gender difference: 5.2 for men, 4.8 for women.
The 14- to 25-year-old group stood out by reporting a frequency lower than all other age groups. But the most striking finding concerns the daily rhythm: flatulence is rare in the middle of the day, then gradually increases to reach a peak between 6 p.m. and 10 p.m.—precisely when the most caloric and high-fiber meals are consumed.
Odorless or Odorous: Two Very Different Origins
Not all intestinal gases look alike. Some simply come from swallowed air during meals or drinks — harmless, odorless, and unrelated to digestion. Others are produced by the billions of gut bacteria that break down foods, especially fibers.
It is this second process that generates sulfur-containing compounds responsible for the characteristic odor. The presence of a smell is therefore not a sign of dysfunction — it reflects an active microbiome and ongoing digestion.
When the Absence of Gas Becomes a Warning Signal
Contrary to common belief, it is not an excess of flatulence that should worry you first. A sudden inability to evacuate gas — especially accompanied by abdominal pain or bloating — may indicate a bowel obstruction or another serious digestive disorder requiring prompt medical consultation.
The researchers emphasize that this study establishes, for the first time, a numerical baseline. Knowing what is normal helps doctors and patients better identify what isn’t — and approach these conversations without unnecessary embarrassment.
