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Stimulant laxative

Senna: uses, side effects & precautions

Also known as Senokot, Ex-Lax (sennosides), Sennosides.

Diese Informationen dienen ausschließlich der allgemeinen Orientierung und stellen keine medizinische Beratung dar. Konsultieren Sie bei persönlichen gesundheitlichen Anliegen stets eine qualifizierte medizinische Fachkraft. Wählen Sie im Notfall Ihre örtliche Notrufnummer.

What it is used for

  • Short-term relief of constipation
  • Clearing the bowel before some examinations (under guidance)

How it works

Senna is a plant-derived stimulant laxative that prompts the muscles of the bowel to contract more, moving stool along and producing a bowel movement, usually overnight.

How it is taken

Comes as tablets, granules, and oral liquid. It is taken by mouth, often in the evening so it works the next morning. Take it exactly as the label or your clinician directs, and use it only for short periods unless advised otherwise.

No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.

Common side effects

  • Stomach cramps
  • Wind
  • Harmless reddish-brown discolouration of urine
  • Loose stools

Serious effects — get help

  • Severe or persistent abdominal pain
  • Ongoing diarrhea with dehydration or salt imbalance
  • Rectal bleeding
  • Signs of dependence or worsening constipation with prolonged misuse

If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.

Interactions to watch

  • Medicines affected by low potassium (some heart drugs like digoxin)
  • Diuretics (water tablets) and corticosteroids (added potassium-lowering effect)
  • Other laxatives

Who should take care

  • For short-term use; long-term reliance can worsen bowel function and lower potassium
  • Avoid if you have a bowel blockage, severe abdominal pain of unknown cause, or certain inflammatory bowel conditions in flare
  • Discuss use in pregnancy and breastfeeding with a pharmacist
  • Not generally for young children without advice
  • See a clinician if constipation is ongoing or you have unexplained changes in bowel habit

Frequently asked questions

When will senna work?
It usually works about 8 to 12 hours after taking it, which is why it is often taken at bedtime.
Can I take it every day?
It is meant for short-term use. Daily long-term use can make the bowel sluggish; see a clinician for ongoing constipation.
Why is my urine a different colour?
Senna can harmlessly tint urine reddish-brown. This is not dangerous, but mention it to your pharmacist if unsure.
Is it safe in pregnancy?
Some forms are used short-term in pregnancy, but check with a pharmacist or doctor first.

Related conditions

Related medicines

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