Not fair to judge this as anything other than what it was: a mini try-out for Renoir to prove to financiers he could make a sound film. Stagey and a bit drawn out, the interest is just slightly more than historical. But Renoir's choice and handling of the material (constipation as social satire) show his interest in theater, farce, and stripping back bourgeois facades to find human, vulgar embarrassment underneath.
Important to note: On purge bébé was made by Renoir simply to prove to financiers that he would be a safe investment once he REALLY got around to making talkies. So it is essentially a director auditioning. And it's a swell audition. Though not very "Renoir." Extremely stagebound. A pretty typical bit of French farce, based on a play by Georges Feydeau. Funny. French funny. But, man: Marguerite Pierry is kick-ass!