What Causes Dark Orange Color Urine And Abdominal Cramps In An Elderly Woman?

Greetings: I am 57 yr old female. Recently lost 23 lbs through the physicians weight mgmt plan and mild to moderate exercise. Approximately 1 month ago I had a colonoscopy; four be-nine pallups removed. I have had increased gas, and over the past two weeks there has been 5 times where my urine is a dark burnt orange brown color. There is no particular time of day when the dark urine comes. The rest of the time it is more of a very light to clear yellow. I also have a cramping, like I am going to have a menstrual cycle, but have not had a cycle in 15 years. My diet consists of high protien and complex carbs (broccoli, sugar peas, carrots, - none of the foods listed that would change the color of urine. Meds include: Atorvastatin 80mg, Nicotinate, Phendimeyrzine.