Diarrhea on a GLP-1 usually shows up in the first weeks or after a dose increase, and it is the mirror image of constipation: the gut is over-stimulated instead of slowed. The food playbook is the classic one — bland, low-fiber, well-cooked foods — with protein kept up so the episode does not cost muscle.
GLP-1 drugs change gut motility; in some people this shows up as loose stools, particularly early in treatment or around dose changes. Most episodes settle as the dose stabilizes.
For most people it settles within a few weeks as the body adapts to the dose. The BRAT-style foods (bananas, rice, applesauce, toast) plus fluids carry most people through the adjustment window.
Do not stop or adjust the dose on your own — that decision belongs to your healthcare provider. The food side is manageable: bland, low-fiber meals and hydration. If diarrhea is severe or lasts beyond a few days, contact your provider.
Water, clear broths and oral rehydration solutions. Avoid sugary drinks, alcohol and excess caffeine — they pull fluid the wrong way.
Severe diarrhea, blood in stool, or inability to keep fluids down for 24 hours — contact your healthcare provider.
This guide presents USDA nutrition data and the diet framework from the JAMA 2025 patient guidance and 2026 European obesity nutrition consensus for informational purposes only. It is not medical advice. If you are concerned about any symptom, contact your healthcare provider.