It is best to skip coffee until your diarrhea settles, because the NIH digestive disease institute (NIDDK) lists caffeinated drinks like coffee, tea, and some sodas among the drinks that could make diarrhea worse. MedlinePlus gives the same advice: avoid caffeine, alcohol, and fizzy drinks. Your main job right now is replacing lost fluid, so drink water and fluids with electrolytes, such as broth, sports drinks, or an oral rehydration solution. NIDDK says most people can go back to their normal diet once they feel like eating again.
Why is coffee a bad idea when you have diarrhea?
NIDDK, part of the National Institutes of Health, tells people with acute diarrhea to avoid foods and drinks that could make it worse. Drinks with caffeine, such as coffee, tea, and some soft drinks, are on that list. MedlinePlus also says to avoid caffeine, alcohol, and carbonated drinks while you have diarrhea.
There is a fluid reason too. MedlinePlus describes caffeine as a diuretic, which means it makes you pee more, and lists dehydration as one effect of too much caffeine. When diarrhea is already pulling water out of your body, you do not want a drink that adds to the loss.
What about what goes in the coffee?
The add-ins can be a problem on their own. NIDDK lists these as things that could make acute diarrhea worse:
- Milk and cream with lactose. Milk products that contain lactose are on the avoid list. MedlinePlus says to limit or cut dairy if it makes diarrhea worse or causes gas and bloating.
- Lots of sugar. NIDDK lists simple sugars, which are often found in sweetened drinks and some fruit juices.
- Sugar alcohols. NIDDK lists foods and drinks with sugar alcohols, such as sugarless gum and candies, and says they can cause diarrhea in some people. If you use sugar-free syrups or sweeteners, check the label.
- Caffeinated sodas. NIDDK names some soft drinks for their caffeine, and MedlinePlus and the NHS both say to avoid fizzy drinks.
What should I drink instead?
NIDDK advises drinking plenty of water and liquids that contain electrolytes, such as broths and sports drinks. Oral rehydration solutions, which contain glucose and electrolytes, are sold at pharmacies.
MedlinePlus suggests 8 to 10 glasses of clear fluids a day, with water as the best choice, plus at least 1 cup (240 mL) of fluid every time you have a loose bowel movement. If you feel sick to your stomach, take small sips often instead of big gulps, as the NHS advises.
If you are an older adult, or you have diabetes, kidney disease, a weak immune system, or another health condition, NIDDK says to talk with your doctor before using oral rehydration solutions, because a specific solution or amount of liquid may work better for you.
- Water, sipped often
- Clear broth, which NIDDK lists as a liquid with electrolytes
- An oral rehydration solution from the pharmacy
- A sports drink, if that is what you have
What if I get a caffeine withdrawal headache?
If you drink coffee every day, stopping suddenly can bring on withdrawal. MedlinePlus lists headaches, drowsiness, irritability, nausea, and trouble concentrating, and says these usually go away after a couple of days.
Some of those, like nausea and feeling tired, can overlap with being sick or dehydrated. If a headache comes with other warning signs, such as a stiff neck, confusion, or a sudden severe headache, do not assume it is withdrawal. Those need care right away.
When should you get care?
In an emergency, call 911Get medical care the same day if you have signs of dehydration (extreme thirst or dry mouth, peeing less than usual, dark urine, feeling tired, dizzy, or lightheaded), 6 or more loose stools a day, a high fever, frequent vomiting or you cannot keep fluids down, severe pain in your belly or rectum, or stools that are black and tarry or contain blood or pus.
See a doctor if diarrhea is not getting better. Sources set this point differently for adults: NIDDK says diarrhea lasting more than 2 days, MedlinePlus says 5 days, and the NHS says more than 7 days. If you are pregnant, over 65, or have a weak immune system, NIDDK says to stay in close contact with your doctor. Go sooner if you feel worse.
Call 911 if you are confused or not responding as usual, vomit blood or something that looks like coffee grounds, have green vomit, have a sudden severe belly pain or headache, have a stiff neck with pain looking at bright lights, have severe trouble breathing, or have blue, gray, pale, or blotchy lips, tongue, or skin.
How our AI doctor decides when to send you to care ›When can I have coffee again?
NIDDK says that in most cases, when you feel like eating again, you can eat your normal diet. None of the sources gives a set time for coffee, so a cautious approach is to wait until you feel better and the diarrhea has settled, then try a smaller cup to see how it goes. NIDDK also notes that some people have trouble digesting lactose for up to a month or more afterward, so milk in your coffee may bother you for a while.
The NHS says diarrhea usually stops within 5 to 7 days. If coffee seems to set off loose stools again and again, even when you are not sick, raise it with a doctor, since NIDDK notes that diarrhea that keeps going has a range of possible causes.
Common questions
Can I drink coffee with diarrhea?
It is best to skip it until the diarrhea settles. NIDDK and MedlinePlus both list caffeinated drinks, including coffee, among the drinks to avoid during diarrhea. Drink water and fluids with electrolytes instead.
Is black coffee better than coffee with milk?
Black coffee avoids the lactose in milk, which NIDDK also lists as something that could make diarrhea worse. But black coffee still has caffeine, so it is still on the avoid list for now.
Can I drink tea or soda instead?
Not if they have caffeine. NIDDK names tea and some soft drinks along with coffee, and MedlinePlus says to avoid carbonated drinks. The NHS also says fizzy drinks and fruit juice can make diarrhea worse.
Does coffee count toward my fluids when I have diarrhea?
It is not a good choice for fluids while you are sick. Caffeine makes you pee more, and the sources advise avoiding it. Water, broth, and oral rehydration solutions are better ways to replace what you are losing.
Can I stay at work if I have diarrhea?
The NHS advises staying off work or school until you have not had diarrhea or been sick for at least 2 days, because stomach bugs spread easily. Your workplace or school may have its own rules.
Pymander is not a replacement for a physician and does not provide medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with questions about a medical condition. If you think you may have a medical emergency, call 911.