Answer
Senna metabolites can harmlessly discolour urine yellow or red-brown. The colour returns to normal after treatment ends.
Sources for this answer
- Senokot 7.5mg/5 ml Syrup 12 Years Plus — Current selected SmPCemc · Summary of Product Characteristics
- NHSNHS · NHS medicine guidance
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.