Celiac disease is defined as a systemic immunological disorder caused by gluten (gliadin and other prolamin) in genetically predisposed individuals, who present with a variety of gluten-dependent symptoms, specific antibodies, the presence of the HLA DQ2 and DQ8 histocompatibility antigen, and enteropathy. Its prevalence, depending on the studied population and methodology, is estimated at 0.75-1.6% of the general population. During the complex immune reaction it induces, most cells involved in inflammatory processes are activated, which leads to the gradual atrophy of intestinal villi and the proliferation of enterocytes within intestinal crypts. The pathogenesis of celiac disease is extremely complicated and is still the subject of research. According to the current diagnostic guidelines, the following criteria should be taken into account: clinical symptoms (intestinal and extraintestinal), the presence of antibodies against tissue transglutaminase in the IgA class, the level of total IgA, and the presence of typical histological changes in duodenal biopsies. Diet-resistant celiac disease is one of the most important clinical challenges, causing serious complications. Currently, the basic method for treating celiac disease is an elimination diet (i.e., the exclusion of products that may contain gluten from the diet), however, new therapeutic strategies are still being sought, mainly based on supplementation with exogenous endopeptidases, modification of the immune response, and the use of zonulin inhibitors and transglutaminase 2 inhibitors. Clinical trials of new drugs are ongoing. The gradually expanding knowledge about the pathogenesis of celiac disease may allow for the development of new therapeutic strategies for both patients with a mild disease course, as well as those that are diet-resistant.