###Human: Is colonoscopy necessary for diagnosis of stomach pain with diarrhea? ###Assistant: Hello. Colonoscopy is an invasive procedure in which we can see the lesions directly. If we have doubt then we can take a biopsy and also if any lesion needs to be treated means it can be treated immediately. It is diagnostic and therapeutic also. CT abdomen, ultrasound abdomen and barium swallow, etc., are available but not possible to take the biopsy or treat the lesions. So, please consult your gastroenterologist. He will examine and treat you accordingly. Take care.