Carry On Again Doctor (1969)

Francis A. Bigger (Frankie Howerd) is posing as a doctor at a busy hospital ward. He manages to convince the doctors to allow him to stay temporarily for a document misplacement issue. However, he is discovered by a vigilant nurse and is promptly removed from the hospital.

Meanwhile, in the executive office, the hospital's administrator, Dr. Ernest Stoppidge (Kenneth Williams), discusses the possibility of a new operation called "Knee Trembler" with Prof. Julius Kelp (Jim Dale) and Dr. Carver (Sid James). The procedure involves inserting a metal knee joint that would alleviate patients' problems.

Prof. Kelp is assigned the responsibility of finding a guinea pig for the trial surgery. He comes across an elderly patient, Miss Fosdick (Joan Sims), who recently injured her leg by slipping on a banana peel. However, due to an administrative mistake, Miss Fosdick is discharged before the surgery can take place.

Meanwhile, Dr. James Nookey (Charles Hawtrey), a notoriously clumsy and accident-prone doctor, falls in love with a nurse, Sandra May (Anita Harris). In an attempt to impress her, he volunteers to be the guinea pig for the "Knee Trembler" operation. However, Prof. Kelp is hesitant and believes James is not a suitable candidate for the procedure.

When the hospital's administrator, Dr. Stoppidge, learns about the potential failure of the operation, he becomes worried about the hospital's reputation. To maintain appearances, he hires an actor, Dick Ablewhite (Peter Butterworth), to pose as a distinguished surgeon to perform the operation on James.

On the day of the surgery, chaos ensues as multiple cases of mistaken identity occur. Another patient, Mr. Barron (Peter Gilmore), mistakenly receives a fertility operation, turning him into a desirable target for every woman he encounters.

During the operation, the real surgeon, Prof. Kelp, arrives and exposes the imposter, Dick Ablewhite. James, unaware of the deception, is confused but relieved to find out that the real surgeon was operating on him. Despite Prof. Kelp's initial doubts, the operation is ultimately a success.

In the end, Dr. Nookey and Nurse Sandra May confess their love for each other. Miss Fosdick, who had been re-admitted to the hospital, winds up with another operation herself, a rare procedure that allows her to walk again. The hospital's reputation is saved when the true success of the "Knee Trembler" operation is revealed.

The film ends with the hospital staff celebrating, James and Sandra embracing, and the bumbling Mr. Barron being chased by a horde of enthusiastic women.