Although most anal and rectal problems can be diagnosed by a physician, many patients are referred to a gastroenterologist, colorectal surgeon or proctologist. The diagnosis of anal and rectal problems typically involves an evaluation of the patient’s medical history, a physical examination and a series of diagnostic tests. While gathering the patient’s medical history, physicians and gastroenterologists generally ask about symptoms, bowel habits and changes in bowel patterns. They may ask if the patient has had similar symptoms in the past or if he or she has a family member with similar symptoms. Patients may be reluctant to discuss these factors, but need to be open and honest to obtain an accurate diagnosis.

The physical examination usually begins with an examination of the anal area. The skin around the anus is examined for any abnormalities. The physician or gastroenterologist will generally test (palpate) for anal reflexes by using light pressure or even tiny pinpricks around the anus. A digital rectal exam is generally performed. A gloved finger is inserted into the rectum to feel for any abnormalities. This may be accompanied by a visual and manual examination of the vagina in women.

Imaging tests help diagnose many anal and rectal problems. The most common of these involve a tiny, lighted camera on a thin tube connected to a monitor. An anoscope or proctoscope uses a short, rigid tube to examine just the anus and rectum. A sigmoidoscope uses a longer, flexible tube capable of extending deeper into the colon. These tools are inserted through the anus. While these procedures may be uncomfortable, they are typically not painful. If the anal and rectal area is sensitive due to a condition, anesthesia may be used. Tissue and stool samples may be obtained during these procedures for biopsy.

Other diagnostic tests for anal and rectal problems include:

• Barium enema. A solution containing barium is inserted into the rectum and colon. Barium acts as a contrast medium to allow the internal structures to show up more clearly on an x-ray.
  
  
• Endoscopic ultrasonography. An ultrasound probe is inserted into the rectum to generate images of the rectal and anal structures including the sphincter muscles.
  
  
• Defecography (proctography). A barium solution is used, followed by an x-ray of the anal and rectal region that is taken while the patient sits on a specially designed toilet. The patient is generally asked to cough, press the buttocks together, defecate and bear down as if trying to defecate. Images can show the muscle movements in the anus and rectum.
  
  
• Anal electromyography. The electrical nerve function of the anus is assessed using tiny needle electrodes inserted into the muscles around the anus.
  
  
• Anorectal manometry. A test that measures the strength of the anal sphincter muscles and rectal sensation. A short, flexible tube is inserted into the anus and rectum to assess the pressure generated by the muscles at rest and when squeezing.
  
  
• Blood and fecal tests. Can be used to identify the presence of infection and rule out other possible causes of symptoms.