Why poop smells
Poop smells mainly because of the gases and compounds produced as food is digested in your gut. Your intestines contain lots of bacteria that help break down leftover food. As they do this, they make smelly waste products.
What causes the smell
- Hydrogen sulfide (rotten-egg smell) is produced when sulfur-containing foods are broken down.
- Indole and skatole come from protein breakdown and contribute to a strong, sometimes musty odor.
- Ammonia and other nitrogen-containing compounds add sharp, pungent notes.
- Short-chain fatty acids like butyrate can give a sour or rancid smell.
Why smells vary
- Diet: Foods like eggs, broccoli, onions, garlic, red meat, and dairy can change smell.
- Digestive health: How well your gut processes food affects odor. Conditions or infections can change smells.
- Medications and supplements: Some medicines can alter stool smell.
- Gut bacteria balance: A mix of bacteria produces different smells; a big change in your diet can shift this balance.
Is it normal to have smells?
Yes. It’s normal for stool to have a smell because digestion and bacteria are always at work in your gut. The exact smell can vary from person to person and meal to meal.
When to talk to a doctor
- Stool that smells unusually strong for a long time, or is accompanied by other symptoms (very pale stools, persistent diarrhea or constipation, abdominal pain, fever, or noticeable weight loss).
- If you notice blood in the stool.
If you have concerns about digestion or smells, it’s okay to talk to a parent, guardian, or doctor. They can answer questions and help if something seems off.