Answer
Senna metabolites can harmlessly turn urine yellow or red-brown; the colour should return to normal after treatment ends.
Sources for this answer
- Senokot 7.5 mg Tablets 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.