However, there are cases where the color may appear yellowish, sometimes referred to as âyellow spermâ or âyellow semenâ. The cause of yellow sperm is uncertain but it is believed that it can be caused by infection, or foods which are rich in sulfur such as garlic and onions.Another possible cause for yellow semen could be the natural thickening of semen; especially if you have not ejaculated for quite some time.he cause of yellow sperm is uncertain but it is believed that it can be caused by infection, or foods which are rich in sulfur such as garlic and onions.
Red dye or purple dye masks the lining of the colon and can interfere with getting accurate results. Here is a Top Five list of red and purple foods and drinks to avoid before your colonoscopy: Jell-OâAvoid strawberry, raspberry, cherry or black cherry and grape. PopsiclesâAvoid any red or purple in a variety pack. Try the natural frozen fruit bars made with real fruit juice.
If your doctor has prescribed a low-fiber diet in preparation for your colonoscopy, there is a wide variety of foods you can eat. Here are some items that can stay on your low-fiber pre-colonoscopy menu: Dairy.