What it is used for

Stomach and bowel cramps, including in irritable bowel syndrome (IBS)
Period cramps
Bladder spasms

Read our guides:

Irritable bowel syndrome (IBS)

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Reducing noisy breathing caused by secretions at the end of life (injection)

How it works

Hyoscine butylbromide blocks acetylcholine in the smooth muscle of the gut, bladder and womb. This relaxes the muscle and reduces cramping pain.

Side effects

Like all medicines, Hyoscine butylbromide can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

dry mouth
constipation
a fast heartbeat
blurred vision

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

eye pain with blurred vision or seeing halos
being unable to pee
severe stomach pain that does not ease

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

See a GP if you have new bowel symptoms, especially if you are over 40, have blood in your poo or are losing weight.
It is different from hyoscine hydrobromide, which is used for travel sickness.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.