Inflammatory bowl diseases, Crohn`s disease and ulcerative colitis, are autoimmune diseases whose etiology hasn’t been completely clarified. Their cause is assumed to be an inappropriate activation of the immune system, which is supported by genetic predisposition, microbiologic and environmental factors. It is noted they appear in developed countries and urban surroundings more often, as well as in people of young age and lately more frequently in the paediatric population. The characteristics of Crohn`s disease are skipping lesions which involve the whole wall of the intestine of the complete digestive system, while ulcerative colitis` lesions affect the top layer of the colon, initially rectum and can extend continuously towards the oral cavity. Clinical signs are abdominal pain, bloody diarrhoea and malnutrition. Extraintestinal symptoms rarely appear. They can be localised on the eye, skin, hepatobiliary system, joints and oral cavity. Oral manifestations of inflammatory bowl diseases are divided into specific ones, which come up rarely, and non specific ones, which are more frequent. They are consequences of nutritional deficiency due to a damaged intestinal mucosa, chronic diarrhoea, surgery of the affected piece of the intestine or low oral intake. Oral manifestations can also occur as side effects of drugs which are used as therapy for the primary disease. The most common lesions are mucogingivitis, cobblestones, indurated tag- like lesions, granulomatous cheilitis, lip swelling, deep linear ulcerations, aphtae, cheilitis angularis, pyostomatitis vegetans, opportunistic infections; a higher prevalence of caries and periodontal disease is also noted. The therapy of oral manifestations consists of a supporting topical therapy which is supposed to calm the symptoms if the systemic treatment of the primary disease doesn’t suffice. In most cases the therapy for gastrointestinal lesions, made with immunomodulators, corticosteroids and biologic drugs, has results in the oral cavity as well