To investigate a case of right mesocolic hernia accidentally found during right hemicolectomy in adults, so as to improve the correct understanding of this disease.

A case of right mesocolic hernia was selected from the Department of Colorectal Surgery of Qilu Hospital of Shandong University, and the relevant literature was reviewed.

The patient was a middle-aged male who underwent laparoscopic right hemicolectomy due to poor conservative treatment for ascending colon diverticulitis. Malrotation of the small intestine was accidentally found during the operation. The operation was successfully completed and the patient was discharged successfully.

Congenital malrotation of the small intestine in adults is rare and usually diagnosed during surgery. Relevant imaging examinations are helpful for diagnosis of the disease. In addition, CT images should be carefully read before surgery to identify possible variations, so as to calmly cope with them during surgery and ensure the life safety of patients to the greatest extent.