Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes What I need to know about Diverticular Disease ?
    ### Response:
    Doctors are not sure what causes diverticular disease. Many think a diet low in fiber is the main cause. Fiber is a part of food that your body cannot digest. It is found in many fruits and vegetables. Fiber stays in the colon and absorbs water, which makes bowel movements easier to pass.
    