<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, My son has just had knee surgery and returned from hospital yesterday afternoon. He slept well last night but woke up this morning with severe 710 pain rate upper abdominal pain about a hand span down from nipple line The pain comes in spasms which last for 7 - 10 minutes and occur every 20 -30 minutes. Medication has been panadol last dose 27 hours ago and tramadol last dose 22 hours ago. He ate normally last night and toileting is normal. Any suggestionsthoughts appreciated.  <response>: Hi. Thanks for your query. Your son has developed severe pain in the upper abdomen days after Knee Surgery, hand-span down the nipple line. Pain comes in spasms lasting for 7 to 10 minutes, and occur every 20 to 30 minutes. Taking Paradox and Tramadol. Ate normally yesterday and toileting is normal. The possible causes are:Acid peptic disease wherein you get gastric or duodenal ulcer or esophagitis. Pancreatitis. I would advise you the following:Start giving him PPI like pantoprazole. Antacid liquids at 3 hourly intervals. Get an Upper GI Endoscopy and CT scan of the abdomen. Clinical evaluation and physical examination by a Doctor, preferably a Gastroenterologist helps more. 