Repeated infection and fluid collection in the pancreas is most probably suggestive of a pseudocyst of the pancreas. The investigation of choice would either be a ERCP or a MRCP. This will enable the surgeon to decide the further line of action.

Hi.
1. Occasionally, acute pancreatitis may be mistaken for acute appendicitis, and the patient goes for appendicectomy. This happens because acute appendicitis is one the many differential diagnoses for acute pain in abdomen which is actually caused by acute pancreatitis. Even I have a personal experience of one such case of acute pancreatitis who presented like acute appendicitis and went for appendicectomy. During this patient's subsequent attacks of pain, the diagnosis of acute pancreatitis was established. This is not always the case, but is possible. Anyway.
2. Considering that appendicectomy was performed for acute appendicitis truly, the subsequent problem of pancreatitis has no relation with the previous appendicectomy. In other words, don't think that pancreatitis is a complication of appendicectomy.
3. Since you haven't mentioned blood investigation reports, I will not be able to define the pathology in your brother's case - whether recurrent acute pancreatitis or chronic relapsing pancreatitis. Anyway. In ~ 40% of cases the exact cause of pancreatitis cannot be ascertained. That is called 'idiopathic' pancreatitis. Nevertheless, keep in mind that eventually, gallstone may turn out to be responsible later although it is not detected in the present imaging investigations.
4. Consider MRCP (Magnetic Resonance CholangioPancreatography) since US and CT scans have failed to detect the cause.
Thanks.

As per your description your brother is suffering from repeated attacks of acute pancreatitis and on investigations he is neither having stone disease or is alcholic. That is a case of Idiopathic pancreatitis. There must be some metabolic cause of it. You should get Lipid profile, Serum calcium levles. You have not mentioned that whether fluid collection in pancreas is increasing or decreasing or stable. Whether along with fluid collection he has problems in other systems of body like renal. respiratory, blood, intestines. Can u send photographs of CT angio of abdomen. He may need endoscopic sphincterotomy (i.e dilating the mouth of pancreatic duct end which is opening into duodenum), if nothing is found, because microlithiasis can be the cause of recurrent acute pancreatitis. If fluid collection in the pancreas is increasing or not decreasing and it is causing symptoms it has to be drained either surgically or endoscopically depending upon the location after viewing the CT scan