This guide provides detailed instructions for patients collecting a 24-hour urine sample for 5-HIAA testing at Tan Tock Seng Hospital. It explains dietary restrictions including avoiding specific foods like avocado, banana, nuts, and vanilla products for 3-4 days before and during collection. The material provides step-by-step collection procedures, proper storage instructions, and important safety warnings about the preservative liquid in the collection bottle to ensure accurate test results.