Gastrointestinal stromal tumor can be found in any area of the gastrointestinal (GI) track such as esophagus, stomach, pancreases, large intestine, small intestine and appendix. Small GISTs often do not cause symptoms, and are usually discovered incidentally on upper GI endoscopy or computer tomography. Large GISTs may cause abdominal discomfort / pain, or even GI bleeding.

Structure of bile duct includes intrahepatic and extrahepatic bile duct, while bile duct cancer can be found in anywhere of the bile duct and can be defined according to the location it has been discovered as below:

• Intrahepatic cholangiocarcinoma
• Extrahepatic cholangiocarcinoma
• Hilar cholangiocarcinoma (Occurs at the junction of extra hepatic bile duct and liver)
• Klatskin Tumour (Occurs at the junction of left and right hepatic bile duct)

The symptoms of bile duct cancer are as well depended on the location of cancer. Commonly seen symptoms include yellowing, stool become pale in color, urine become deep in color, abdominal or back pain, unknown reason weight loss and no feeling of hunger. Fever may occur due to cholangitis, which is a result of cancerous obstruction.

Pancreases is an organ located behind the stomach. Its function is to provide digestive enzymes and to regulate hormones of metabolism. There is no significant symptom in the early stage of pancreatic cancer. Thus, it is difficult to be detected. Once symptoms appear, they are mostly at a later stage of stage that could not conduct operation procedure. The symptoms of pancreatic cancer include yellowing, stool become pale in color, urine become deep in color, abdominal or back pain, unknown reason weight loss and no feeling of hunger.

Although most of them are benignant, there are risks of becoming malignant. Small size mucinous cysts are mostly discovered by chance, while large size mucinous cysts will cause abdominal pain. The most common type of mucinous cysts are:

1. Intraductal papillary mucinous neoplasm (IPMN), with subtype main duct, branch duct and mix type.

2. Mucinous cystic neoplasm (MCN)

Usually serous cysts are benignant and the most common type is serous cystadenoma. Serous cystadenoma is featured with microcysts and is discovered by chance. Abdominal pain may result from large serous cystadenoma.

Pancreatic cystic lesions can be divided into the below:

1. Non-neoplastic cysts – simple cyst, pseudocyst

2. Neoplastic cysts – this can further be divided into serous and mucinous

Pancreatitis can be divided into chronic or acute type. Chronic type may last for a few years, while acute type will appear suddenly and last for a few days. Both types will result as below:

• Upper abdominal pain, this pain may refer to back pain
• Vomiting

Other gastrointestinal or pancreatic/bile diseases may also lead to the above symptoms, thus, clinical symptoms and image check such as computer tomography are needed for confirmation of the disease.

If the bile stone is causing obstruction to the bile duct, this may result in the below:

• Sudden and severe pain in the abdominal area
• Back pain between your shoulder blades
• Nausea or vomiting
• Yellowing of your skin and whites of your eyes
• Fever with chills