Physical Examination 
• Abdominal mass or painful distension. 
• Rectal bleeding—possibly caused by ulcerations in the gastrointestinal tract— which may result in anemia . 
• A partial or complete obstruction of the intestinal tract.
• Jaundice , which may be due to a tumor in the duodenum or to liver metastasis .
• Bowel kinking (intussusception). 
• Often fatty fluid (chylous ascites) can collect in the abdomen.

Blood and Other Tests 
• Blood counts usually show iron deficiency anemia when bleeding occurs.
• The level of carcinoembryonic antigen (CEA) in the blood is often elevated with adenocarcinomas.

Imaging 
• The most useful x-rays are an upper gastrointestinal and a small bowel series. These can detect a small cancer
  (often a "napkin ring" deformity) or a polyp .
• X-rays showing small bowel thickening with ulceration may indicate a lymphoma.  An abdominal CT scan can
  help identify lesions outside the bowel, including metastases.