<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi doctor, I have been experiencing some symptoms related to my rectum like frequent constipation, rectal bleeding, and abdominal cramps. What could be the issue and what medical tests do I need to take?  <response>: Based on your symptoms, I would recommend a thorough rectal examination, a sigmoidoscopy or colonoscopy to check for any abnormalities in your rectum or colon, and also some hematologic tests such as a complete blood count, glucose measurement, electrolytes panel, and kidney function tests to assess the overall health of your body. 