CAT (computed axial tomography) scans can be used to identify the causes of various digestive symptoms including abdominal pain, difficulty swallowing (dysphagia) and vomiting. They may be used to diagnose the following conditions that affect the digestive system:

• Appendicitis. A condition in which a small, finger-shaped pouch attached to the large intestinelarge intestine called the appendix becomes blocked or inflamed. The cross-sectional images that result from a CAT acan can help distinguish whether appendicitis or another abdominal condition causing similar symptoms is present.
  
  
• Cirrhosis of the liver. Scarring of the liver caused by disease. CAT scans can reveal damage to or inflammation of the liver.
  
  
• Colon disorders. The colon is the part of the large intestine that extends from the cecum to the rectum. CAT scans can help reveal the location of obstruction inside the colon. In addition, CAT scan technology can be used to perform a virtual colonoscopy, in which two- and three-dimensional images of the colon are created.
  
  
• Crohn's disease. A type of inflammatory bowel disease (IBD) that causes inflammation anywhere in the intestines. A CAT scan can be used to help detect an abscess (localized collection of pus in the body), obstruction or fistula (abnormal passage from a hollow organ to the body surface, or from one organ to another) in the abdomen of patients with this condition.
  
  
• Diverticulitis.  Occurs when diverticula or small, abnormal sacs in the large intestine become inflamed and infected.
  
  
• Gallstones. These form when bile stored in the gallbladder hardens into pieces of stone-like material. Gallstones can cause health problems such as pancreatitis and may need to be surgically removed. Ultrasound is more commonly performed to diagnose gallstones, but a CAT scan may be performed for potential problems in the pancreas due to gallstones.
  
  

  

• Internal fistula. An abnormal passageway that develops between two areas of the digestive tract. It can develop between two areas of intestine or between an intestine and a separate organ.
  
  
• Intestinal ischemia. Reduction in blood flow to the colon or small intestine. CAT scans can help diagnose this condition, particularly when an obstruction of a vein is the suspected cause of the condition.
  
  

  

• Intussusception. A condition in which one section of the small bowel or colon tunnels into an adjoining section.
  
  
• Pancreatitis. Inflammation of the pancreas, a gland that secretes digestive enzymes into the small intestine. These enzymes help digest fats, proteins and carbohydrates. Pancreatitis can be acute (short-term) or chronic (long-term) in duration. CAT scans can reveal damage to and inflammation of the pancreas. These tests can also reveal the presence of pseudocysts, which are accumulations of fluid and tissue debris.
  
  

  
  

• Volvulus. A condition in which a portion of the intestine twists around itself. It occurs most often in the colon, but also can occur in the stomach or the small bowel. CAT scans can reveal the degree of twisting and failure of normal rotation (malrotation) that is present, as well as whether a hole (perforation) has appeared in the colon.
  
  
• Cancer. CAT scans are often used to search for tumors and other abnormalities that may indicate cancer of the digestive tract, such as cancer of the pancreas, liver, colon or rectum.