Brown has a wide normal range and is influenced by bile and diet. Green can occur when material moves quickly through the gut or after eating strongly colored foods.
What to keep in mind
Pale or clay-colored stool, especially when persistent, can merit medical evaluation. Black tarry stool or significant red blood can indicate bleeding and needs prompt attention, though foods and medicines can sometimes change color too.
A photo or tracker can help you describe a pattern, but it cannot establish a diagnosis. When something feels wrong, contact a qualified clinician.