The case of a 27-year-old woman, admitted to our surgical ward with symptoms of epigastric-ache, postmeal vomiting and significant weight loss, is reported. Clinical and radiographic suspicion of mesenterium commune, with duodenal compression due to bands, requested an explorative laparatomy that confirmed the mesenterium commune presence with left caecum and colon adhesion and left Bochdaleck hernia, which is rare in adult age.