Managing Diarrhea on GLP-1

When to Expect It

Diarrhea affects roughly 1 in 4 people who take a GLP-1 medication. It is less common than nausea but about as common as constipation. It is most likely to happen during the first few weeks after starting the medication or after a dose increase.

GLP-1 medications work partly by changing how quickly food moves through the digestive tract and how the gut handles fluids. For some people, this leads to loose or more frequent stools. These symptoms are usually mild to moderate and tend to improve as the body adjusts to each dose.

Diarrhea does not mean the medication is not working or needs to be stopped. That said, adding too much fiber too quickly — a common change when starting a healthier diet — can make diarrhea worse, so adjusting fiber intake is often part of the solution.

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Not All Fiber Is the Same During Diarrhea

Soluble Fiber  ✓  Helps

Absorbs water and forms a gel that bulks up loose stools. Sources: oats, bananas, applesauce, canned pumpkin, cooked carrots and psyllium supplements (e.g., Metamucil). Focus on these during an active episode.

A note about other soluble fibers: Not all soluble fiber forms a gel. Some soluble fibers are quickly broken down by gut bacteria instead of bulking up stool. These include:

• Established prebiotics such as inulin and fructooligosaccharides (FOS), found in chicory root, garlic, onions, and artichokes, and sold as prebiotic supplements. These have the strongest evidence for feeding beneficial gut bacteria.
• Fibers with prebiotic properties such as wheat dextrin (the ingredient in Benefiber). These also feed gut bacteria and support digestive health over time, but are not yet classified as full prebiotics.

💡Both types can cause gas and bloating, and neither will firm up loose stools. While they support long-term gut health, they are not helpful during active diarrhea. Stick with gel-forming soluble fibers (listed above) when symptoms are active

Insoluble Fiber  ✗  Avoid During Flare

Speeds gut movement — can make diarrhea worse. Sources: raw vegetables, bran cereals, whole wheat, nuts, seeds. Temporarily reduce during active symptoms.

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How to Manage It

Nutrition Strategies

• Focus on soluble fiber foods during an active episode (see panel above)
• Eat smaller, more frequent meals — large meals can worsen diarrhea
• Choose bland, low-fat foods that are well tolerated: white rice, cooked carrots, bananas, plain toast, applesauce, plain boiled chicken with the caveat that there is no need to limit yourself to only these foods — eat a normal diet as tolerated.
• Avoid high-fat, greasy, or very spicy foods temporarily
• Limit sugar alcohols (sorbitol, mannitol, xylitol) — often found in sugar free gum, candy, diet products and artificial sweeteners- these can worsen loose stools
• Reduce caffeine and carbonated beverages temporarily

Hydration & Electrolytes

• Diarrhea causes significant fluid and electrolyte loss — replacing both is important critical
• Sip fluids consistently — small amounts often, not large gulps throughout the day in small amounts rather than large gulps.
• Good options include water, broth, small amounts of diluted juice (such as diluted apple juice or white grape juice), and oral rehydration solutions (such as Pedialyte or similar electrolyte drink mixes). Avoid drinking large amounts of full-strength fruit juice, as the high sugar content can make diarrhea worse.
• If diarrhea is frequent or lasting more than a day, do not rely on plain water alone — add an oral rehydration solution to replace lost sodium and potassium.
• Signs of dehydration to watch for: dark urine, dizziness, dry mouth, fatigue. If you notice these, increase your fluid and electrolyte intake and contact your provider if they do not improve.

Behavioural Strategies

• If you increased fiber recently, slow down — add one new food at a time and give your body a few days to adjust before adding another.
• Track what you eat and when symptoms hit — a simple food and symptom diary, even for a few days, often reveals individual triggers.
• Gentle movement (light activity such as walking) is fine and may support digestion, but avoid intense exercise while diarrhea is active as  high-intensity activity can worsen GI symptoms.
• Stress can worsen GI symptoms — deep breathing exercises, rest, or other relaxation techniques may help during a flare
• Don't eliminate all fiber permanently — the goal is adjustment, not avoidance.Once symptoms settle, gradually reintroduce a variety of fiber-rich foods.

Contact Your Care Team If…

Reach Out — Don't Wait It Out

• You are losing weight too fast.
• Diarrhea has lasted more than 2–3 days without improvement.
• You are having more than 4 loose stools per day.
• Diarrhea is interfering with your daily activities or sleep.
• You are unable to keep up with fluid intake.
• Symptoms started or got significantly worse after a dose increase — your provider may need to adjust your dose or slow the titration schedule.
• You are losing weight faster than expected.

Seek Urgent or Emergency Care If…

Go to urgent care or the emergency department if you experience any of the following:

• Signs of significant dehydration: dizziness or fainting when standing, no urination for 8 or more hours, rapid heart rate, or confusion.
• Blood or mucus in your stool.
• Severe abdominal pain, especially if it radiates to your back — this could indicate pancreatitis, which requires immediate evaluation.
• High fever along with diarrhea — fever is not typical of medication-related diarrhea and may signal an infection.
• Diarrhea that is profuse, watery, and uncontrollable.
• Extreme weakness or inability to stand.

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_{This guide is for educational purposes only. It does not take the place of personalized medical advice from your health care provider. Always consult your Onsera care team before making any changes to your medication or treatment plan}