Rhubarb. For dark brown or black urine to occur, we‘re talking about really large doses of rhubarb. Let‘s just say you‘re a rhubarb pie fanatic… and who isn‘t? You would have to be eating rhubarb pie for every meal and then some more for snacks. Smaller amounts of rhubarb would turn your urine orange. If you‘re eating enough rhubarb to cause black urine, then you may have other things to worry about… such as difficulty finding friends when you always have a stalk of rhubarb in your mouth.
Fava beans. Who eats fava beans? Lots of people, apparently. These beans are also called broad beans and horse beans. Broad beans are rich in l-dopa. L-dopa is naturally occurring in your body, but high quantities can create a brown or black urine color.
Sorbitol. Naturally occurring in fruits such as apples, pears, peaches and prunes, sorbitol is used as a sugar substitute in sugar free gum as some drinks, ice cream, mints, even cough syrup. It can cause or worsen upset stomach (ibs), cramping, and diarrhea, especially with high dosages. And yes, it can cause black urine.