Hi Mark, How are you? I am so sorry to hear about your father s diagnosis. Vomitting in pancreatic cancer can occur due to two reasons - the tumor has grown sufficiently big to close of the lumen of the intestine and hence causing a mechanical blockage of the intestine or that it has affected the nerves supplying the stomach causing it not to clear the contents efficiently leading to vomiting. But by reading your description it looks more like the first scenario where there seems to be a mechanical blockage. The green colored vomit is due to the bile which is refluxing back into the stomach. This can cause severe stomach pain and also bitter taste in the mouth. Certain medications will help control the symptoms - antacids (pantoprazole, omeprazole etc) and syrup sucralfate has helped a lot many of my patients get relief from the symptoms. Also if there is indeed a mechanical obstruction, you should explore the possibility of getting a stent placed into the blocked portion of the intestine. This will help him a lot especially allowing to eat normally. Hope this helps and hope your dad starts to feel better. Please do not hesitate to contact me for any further clarifications needed. Dr Suresh Raghavaiah. Liver and Pancreas cancer specialist.