Quick answer

Yes, anxiety can directly cause diarrhea in dogs, a condition known as stress colitis. Emotional stress triggers a surge of cortisol and adrenaline, which speeds up intestinal contractions (hypermotility), alters the gut microbiome, and causes soft stool, mucus, or fresh blood in the feces.

Understanding Stress Colitis and Hypermotility

The gut and brain are linked via the vagus nerve. When a dog
experiences environmental anxiety (boarding, thunderstorms, fireworks,
separation), stress hormones disrupt normal colonic fluid absorption,
rapidly emptying the large intestine before stool can form properly.

Managing Stress-Induced GI Distress

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