According to Wikipedia, and probably some doctors too. A perforated ulcer is a condition in which an untreated ulcer can burn through the wall of the stomach (or other areas of the gastrointestinal tract), allowing digestive juices and food to leak into the abdominal cavity. Treatment generally requires immediate surgery.
So, why does someone describe a delicious hearty meal as “stick to your ribs”? If food is sticking to your ribs you probably have a perforated ulcer and require medical attention.