This patient with a long psychiatric history was found to be eating a lot of hair and eventually starting vomiting.

CT shows a large mass completely distending the stomach consistent with a giant hairball based on the given history.

CT in the lung/air window shows a few tiny foci of air outside of the stomach (arrows), not where there should be any air at all. This is consistent with a small perforation of the stomach.

See here for another case of bezoar causing stomach obstruction.