What causes a sour, foul smell in stool?
Disease description:
I don't know what I ate these past couple of days, but my stool has been emitting a sour, foul odor when I defecate, which is really nauseating. I have no idea why. Doctor, what causes stool to have a sour, foul smell?
Doctor's answer (1)
Dr. Shen Yonghua
The occurrence of a sour or foul odor in stool may be related to several factors, with the following being common causes:
1. Dietary factors: Consuming excessive amounts of high-protein and high-fat foods, such as meat and dairy products, may lead to the production of gases like hydrogen sulfide during digestion in the intestines, resulting in a distinctly sour or foul-smelling stool.
2. Indigestion: When secretion of digestive enzymes is insufficient or digestive function is weakened, food remains in the intestines for a longer period. Bacteria then break down undigested food residues, producing more odor-causing substances and intensifying the smell of the stool.
3. Imbalance of intestinal flora: Beneficial and harmful bacteria in the gut maintain a dynamic balance. If this balance is disrupted—such as from excessive antibiotic use, chronic stress, or irregular lifestyle habits—the number of harmful bacteria may increase, leading to the production of more odoriferous metabolic byproducts.
To address these issues, one can make improvements by adjusting dietary habits, increasing fiber intake, engaging in appropriate physical activity to promote gastrointestinal motility, and using probiotics to regulate gut flora. If the sour or foul odor in stool persists or is accompanied by other discomfort symptoms, it is advisable to seek medical attention promptly.
