Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Gastrointestinal Carcinoid Tumors ?
    ### Response:
    Some gastrointestinal carcinoid tumors have no signs or symptoms in the early stages.Signs and symptoms may be caused by the growth of the tumor and/or the hormones the tumor makes. Some tumors, especially tumors of the stomach or appendix, may not cause signs or symptoms.
    