Hi there, This could be due to a number of things. It could be simply a red coloring due to the high amount of cranberry juice, or your stomach could be irritated from the ibuprofen, which can cause ulcers. Another reason could be hemorrhoids. I would give it a couple days and stop the medications, and see how the bleeding went. If you have increasing abdominal pain, more blood, feel dizzy, have a high heart rate, I d seek medical attention immediately. Make sure you stay well hydrated. I hope this answers your questions. Please feel free to contact me should you have any further questions.