Diarrhoea in adults - Treatments

Medicines that slow down bowel movements

These medicines are also known as antimotility drugs. They work by slowing down the action of your bowels. They include:

• loperamide (brand name Imodium)
• co-phenotrope (Lomotil).

You can buy loperamide yourself from a pharmacist. You can also buy co-phenotrope over the counter as long as you're over 16 years old.

Some good-quality studies have found that loperamide helps clear up your diarrhoea more quickly. In some studies, people who took it were better after a day.[1] [2] Loperamide can help people who get diarrhoea when travelling as well as people who get it at home. One study found that it is likely to work for travellers' diarrhoea if you take it with an antibiotic.[3]

Taking co-phenotrope for diarrhoea can also help. It means you don't need to go to the toilet as often.[4] But in the studies we looked at, people's diarrhoea didn't clear up any faster.

You may get constipated if you take loperamide. In one of the studies, a quarter of people taking loperamide got constipation, compared with 7 in 100 people taking a dummy treatment (placebo) for comparison.[1]

Some people get other side effects from loperamide. These include dizziness, drowsiness or a dry mouth.[5] [6]

You shouldn't take loperamide if you have a fever, or if there's blood or mucus in your stools.[5] If you have these symptoms, see a doctor.

You should stop taking loperamide and see your doctor straight away if you have any of these side effects, which could be serious:[5] [6]

• A bloated abdomen
• Constipation
• Loss of appetite
• Severe stomach pain with nausea and vomiting
• A rash.

The research on co-phenotrope didn't mention side effects. But we do know that if you take it regularly you can become dependent on it.[6] Being dependent means you get unpleasant withdrawal symptoms when you stop taking it. It can also react with other drugs, so it's important to check with your doctor or pharmacist before you take it.

Stop taking co-phenotrope straight away and see your doctor if you have any of these symptoms:[6]

• Severe nausea and vomiting
• Severe stomach pain
• A bloated abdomen
• Loss of appetite
• Severe drowsiness
• Palpitations (a fast, irregular heartbeat)
• Swelling
• A rash
• Dry skin, nose or mouth
• Difficulty breathing
• Seizures.

Antibiotics

Antibiotics are drugs that kill bacteria. There's quite a lot of research to show that antibiotics work as a treatment for diarrhoea . But not all diarrhoea is caused by bacteria, so antibiotics aren't the right treatment for everyone. Your doctor may do tests to see what kind of diarrhoea you have.

Some antibiotics used to treat diarrhoea are:

• ciprofloxacin (Ciproxin)
• levofloxacin (Tavanic)
• ofloxacin (Tarivid).

We found five good-quality studies that show antibiotics can help you get better more quickly.[7] [8] [9] [10] [11] And you probably won't need to go to the toilet as often.[7] [8] [10] [11] Antibiotics can also help you recover from a fever.[9] [11]

There's also good research to show that antibiotics can help you recover more quickly from diarrhoea if you're travelling abroad.[12] [13] [14] In one study, people who took antibiotics got better in about a day, on average.[15] People who didn't take antibiotics took about three days to recover.

One study found that taking antibiotics with another treatment called loperamide works faster than taking antibiotics on their own.[16]

However, antibiotics can have side effects. Some of the side effects may be similar to the symptoms you want treated (such as nausea, a stomach ache or diarrhoea). The side effects that people in studies have reported include:[6] [8] [14]

• Diarrhoea
• Feeling sick
• Muscle aches
• A headache
• A stomach ache
• A rash
• Trouble sleeping
• Feeling dizzy
• Feeling tired.

These side effects aren't usually serious. In studies, not many people stopped taking their antibiotics because of side effects. And the side effects go away when you stop taking the drug.[12]

Most doctors are careful not to prescribe antibiotics unless they think you really need them. This is because antibiotics may not work as well in the future if they are used too much. Bacteria can become resistant to them.[8] [12]

Rehydration salts to add to drinking water

Diarrhoea can make your body lose water (you get dehydrated). So make sure you drink plenty of water or soft drinks. Your doctor or pharmacist may also recommend rehydration salts that you add to drinking water. These are designed to help replace fluids and mineral salts your body may have lost.

You can buy these drinks as sachets of powder or tablets. Some have flavours or sweeteners to make them easier to drink. Some brand names are Dioralyte, Electrolade and Rapolyte.

Rehydration salts are often recommended for children with diarrhoea. But, for adults, there hasn't been any research to tell us whether they're better than drinking water or soft drinks.

Bismuth

A chemical called bismuth is sometimes used to treat diarrhoea. The brand name for bismuth is Pepto-Bismol. It's sometimes sold as a cure for indigestion. You can buy it yourself from a pharmacist. It comes as a liquid.

Bismuth is designed to coat the inside of your bowels and help to kill bacteria. It may help some people with travellers' diarrhoea but we can't say for sure.[17] It may also help prevent travellers' diarrhoea.[18]

Side effects from this drug are rare and not usually serious. Your tongue may change colour and you may get black stools, but these side effects go away when you stop taking the drug.[19]

People who are allergic to aspirin and women who are pregnant shouldn't take bismuth.[18]

Kaolin

Kaolin (KLN) is a medicine sometimes used for diarrhoea. It is designed to absorb substances that might irritate your gut (intestines). You can buy it from a pharmacist without a prescription, and it comes as a liquid you swallow. But kaolin is not recommended for short (acute) attacks of diarrhoea. You should have a doctor's diagnosis for the cause of your diarrhoea before you take kaolin.[6]