Diagnostic tests used to diagnose diseases of the digestive system include:
Colonoscopy: It is a procedure used to view large intestine (colon and rectum) using an instrument called colonoscope (a flexible tube with a small camera and lens attached). The procedure can detect inflamed tissue, ulcers, and abnormal growths. It is used to diagnose early signs of colorectal cancer, bowel disorders, abdominal pain, muscle spasms, inflamed tissue, ulcers, anal bleeding, and non-dietary weight loss.
The procedure is done under general anesthesia. The colonoscope is inserted into the rectum which gently moves up through the colon until it reaches the caecum (junction of small and large intestine). Colonoscopy provides an instant diagnosis of many conditions of the colon and is more sensitive than X-ray. The colonoscope is then withdrawn very slowly as the camera shows pictures of the colon and rectum onto a large screen. Polyps or growths can also be removed by colonoscopy which can be sent later for detection of cancer.
Flexible Sigmoidoscopy: It is a procedure used to see inside the sigmoid colon( the last one-third of the colon) and rectum. The flexible sigmoidoscope is a special camera which can examine the left side of your large bowel and provide a lot of information to your physician.
Flexible sigmoidoscopy can detect inflamed tissue, abnormal growths, and ulcers. The procedure is used to look for early signs of cancer and can help doctors diagnose unexplained changes in bowel habits, abdominal pain, bleeding from the anus, and weight loss.
During a flexible sigmoidoscopy, patients lie on their left side on an examination table. The doctor inserts a long, flexible, lighted tube called a sigmoidoscope into the anus and slowly guides it through the rectum and into the sigmoid colon.
A small camera mounted on the scope transmits a video image from inside the colon to a computer screen, allowing the doctor to carefully examine the tissues lining the sigmoid colon and rectum.
Upper GI endoscopy is a procedure performed to diagnose and in some cases, treat problems of the upper digestive system. Upper GI endoscopy can be helpful in the evaluation or diagnosis of various problems, including difficult or painful swallowing, pain in the stomach or abdomen, and bleeding, ulcers, and tumors. An upper GI endoscopy is both diagnostic and therapeutic. This means the test enables a diagnosis to be made upon which specific treatment can be given. If a bleeding site is identified, treatment can stop the bleeding, or if a polyp is found, it can be removed without a major operation. Other treatments can be given through the endoscope when necessary.
Upper GI endoscopy is usually performed on an outpatient basis. The endoscope is a long, thin, flexible tube with a tiny video camera and light on the end. By adjusting the various controls on the endoscope, the endoscopist can safely guide the instrument to carefully examine the inside lining of the upper digestive system. The high quality picture from the endoscope is shown on a TV monitor; it gives a clear, detailed view. In many cases, upper GI endoscopy is a more precise examination than X-ray studies.
Endoscopic retrograde cholangiopancreatography (ERCP) enables the physician to diagnose problems in the liver, gallbladder, bile ducts, and pancreas. ERCP combines the use of X-rays and an endoscope, which is a long, flexible, lighted tube. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject dyes into the ducts in the biliary tree and pancreas so they can be seen on X-rays. ERCP is used primarily to diagnose and treat conditions of the bile ducts, including gallstones, inflammatory strictures (scars), leaks (from trauma and surgery), and cancer. ERCP may be necessary to find the cause of jaundice, upper abdominal pain, or unexplained weight loss.
Liver Biopsy: A liver biopsy is a procedure whereby small pieces of liver tissue are removed in order to be sent to a laboratory for examination. It is very helpful in the diagnosis of diseases that affect the liver. The three main types of liver biopsy are percutaneous, transvenous, and laparoscopic. Other techniques for obtaining liver biopsies are with fine needle aspiration as well as open surgery. A liver biopsy is performed when a liver problem is difficult to diagnose with blood tests or imaging techniques, such as ultrasound and X-ray. More often, a liver biopsy is performed to estimate the degree of liver damage, a process called staging. Staging helps guide treatment for liver disease.