The present invention relates to a small interfering RNA (siRNA) being 2-O-methyl modified and there being attached thereto by a phosphodiester bond a position 3, wherein group R in position 3, wherein R is selected from among: a C1-C6 alkyl substituted with at least one -OH group a C4-C6 cycloalkyl substituted with at least one -OH group a C4-C6 heterocycloalkyl a heteroalkyl chain having between 2 and 7 atoms, wherein at least one is an oxygen atom or a sulphur atom, the chain preferably being substituted with at least one -OH group and a heteroaryl the ring whereof being formed of between 3 and 6 atoms and at least one of said atoms is an oxygen atom. The present invention furthermore refers to the use of said siRNA for the treatment of inflammatory diseases, preferably inflammatory bowel disease.
