Fluids, Caffeine, Arabic Coffee and Your Gut

Not drinking enough, or losing fluid through heat, vomiting or diarrhoea, makes stools harder and can cause dehydration. Coffee stimulates the gut: it can increase stomach acid and trigger the urge to pass stool in some people, which helps those with constipation but may worsen diarrhoea or irritable bowel syndrome. Caffeine can relax the muscle at the lower end of the gullet, which may worsen reflux in some individuals, although studies on coffee and reflux give mixed results. Fizzy drinks release gas and can cause bloating and belching. Sugar alcohols and large amounts of fructose in some drinks can cause loose stools.

Most adults drink caffeinated drinks daily. Mild dehydration and constipation are common, particularly in hot weather, when physically active, when ill, and during fasting. At the same time, sugary soft drinks, sweetened tea and energy drinks are widely consumed and are linked to weight gain, type 2 diabetes and fatty liver disease.

Serving Arabic coffee and dates is an important custom of hospitality, and accepting a cup or two is entirely reasonable; you can signal that you have had enough by gently shaking the cup. Arabic coffee is usually less strong in caffeine per cup, but the number of cups adds up in gatherings, and it is often mixed with sweets, so watch the total. In the heat of Saudi summers, and during Hajj and Umrah, fluid needs rise: drink water regularly, avoid long periods in the sun, and use rehydration solutions if you have diarrhoea. During Ramadan, aim to drink water steadily between iftar and suhoor, limit tea and coffee which can promote fluid loss and poor sleep, and avoid very salty, spicy or sugary foods that increase thirst. Zamzam water and tap water are both fine for drinking from a safety point of view for most people, provided bottled or stored water is kept clean. Be cautious of energy drinks, which contain high caffeine and sugar.

Dehydration is judged from symptoms, urine colour and amount, pulse, blood pressure and, if needed, blood tests of kidney function and salts. For symptoms linked to coffee or drinks, the simplest test is a trial: record your symptoms, then remove or reduce the suspected drink for two weeks and see what changes. If heartburn, swallowing problems or other warning signs persist, your doctor may recommend endoscopy or other tests.

Make fluids easy to reach and notice your own body signals.

• Sip water through the day. Pale yellow urine is a good sign you are drinking enough.

• Drink more in hot weather, when exercising, in Hajj and Umrah crowds, and when you have vomiting, diarrhoea or fever.

• Do not drink large amounts of coffee or tea close to bedtime, and have coffee after, not instead of, a meal if it irritates an empty stomach.

• If you have reflux, try coffee in smaller amounts, not late in the evening, and see whether it is a personal trigger.

• Count all caffeine sources: coffee, tea, cola, energy drinks and chocolate.

Choose drinks that hydrate without extra sugar.

• Make water your main drink; flavour it with lemon, mint or cucumber if you like.

• Arabic coffee in small cups, with cardamom and little or no sugar, is reasonable for most healthy adults; avoid adding large amounts of sugar or syrups, and be aware that serving dates alongside adds sugar.

• Limit sugary soft drinks, sweetened tea, flavoured coffee drinks, juice and energy drinks. Whole fruit is better than juice.

• Take tea and coffee between meals rather than with meals if you have low iron, since they reduce iron absorption from food.

• Do not restrict or increase your fluids if your doctor has given a specific limit, as in advanced liver, kidney or heart disease or low blood sodium.

• During diarrhoea or vomiting, use an oral rehydration solution from the pharmacy rather than only plain water, soft drinks or juice.

Some medicines change how much fluid you need or how caffeine affects you. Never change a prescribed dose by yourself.

• Diuretics (water tablets) and some blood pressure medicines increase fluid loss; follow your doctor’s advice on fluids.

• Caffeine can interact with some medicines, including certain antibiotics and thyroid or asthma medicines; ask your pharmacist.

• Oral rehydration salts replace water and salts lost in diarrhoea and are safe for most people; ask for advice for babies and young children.

• Avoid stimulant laxatives and anti-diarrhoea medicines as a habit; ask your doctor if bowel problems persist.

Procedures are needed only for complications of drinks or fluid loss, or for persistent symptoms.

• Severe dehydration is treated with fluids through a vein in hospital.

• Upper endoscopy can look for reflux damage, ulcers or other causes if warning signs or lasting symptoms are present.

• Blood tests check kidney function and salts after significant dehydration.

The European Food Safety Authority (2015) concluded that up to 400 mg of caffeine a day (about three to five small cups of coffee, depending on strength) from all sources does not raise safety concerns for healthy adults, that single doses up to 200 mg are safe, and that pregnant women should keep to 200 mg daily. EFSA (2010) set adequate total water intakes of about 2.0 litres a day for women and 2.5 litres for men, including water from food; needs rise with heat and activity. Several large cohort studies and meta-analyses link regular coffee drinking with lower risk of chronic liver disease, cirrhosis and liver cancer, and the 2024 EASL-EASD-EASO guideline on metabolic dysfunction-associated steatotic liver disease mentions coffee as beneficial in fatty liver, although these are observational findings and do not prove cause. Coffee is also associated with a lower risk of gallstones. For reflux, the American College of Gastroenterology guideline (2022) does not recommend routine avoidance of coffee, but advises avoiding foods and drinks that are your own triggers. For constipation, extra fluids help mainly people who are dehydrated; adding fluids beyond normal needs has limited proof. Studies on Arabic coffee specifically are few, so conclusions are drawn from coffee research in general. Sugar-sweetened drinks are linked to weight gain, type 2 diabetes and fatty liver, and the World Health Organization advises limiting free sugars to under 10% of energy. The World Health Organization advises against the use of non-sugar sweeteners to control weight (2023).

Good hydration and sensible caffeine use are simple, low-cost habits that benefit the gut for most people. If a specific drink causes symptoms, reducing it usually brings relief within days to weeks. Dehydration from illness is usually corrected quickly with fluids, but severe cases need hospital treatment.

• How much fluid should I drink each day with my conditions and medicines?

• Is coffee making my reflux, diarrhoea or irritable bowel worse?

• Is coffee safe or helpful with my liver condition?

• Is it safe for me to fast and how should I drink during Ramadan?

• Which drinks should I avoid if I have low iron?

This guide comes from the Saudi Gastroenterology Association (SGA) patient library, prepared by the Approved for publication by SGA; individual clinician review is ongoing. Last reviewed: 2026-04-24. It is for education and does not replace your doctor's advice.