Hi, right side of abdominal discomfort generally happens due to problem in
liver/ gall stone or gastritis and rarely due to infection in right part of colon .
Oily stool can be due to pancreatic deficiency.
Kindly get a ultrasound of abdomen to rule out liver and biliary / pancreatic causes. Take light food for few days. Get a ultrasound of abdomen to rule out the above mentioned causes.