SummaryThis work recalls first of all some general notions regarding the dolichocolon, its nature and pathogeny.It classes the dolichocolon in 2 categories : organic dolichocolon having a real excess of length of the intestine, and the functional dolichocolon, due to the lack of tonicity of the lengthy muscular bands of the colon.It recalls the multiplicity of the causes which can interfere in the pathology of both these types of dolichocolon and among these causes, the character of hypothyroïdy is put into light.In a serie of 127 cases of dolichocolon studied in the course of these last 6 years, eighteen times i. e. nearly in 15 % of these cases, the hypothyroïdy, light or certain, interferes in the pathogeny of the affection.If the hypothyroïdy is so often the cause of dolichocolon, of course, the dolichocolon is usual in the hypothyroïdy where it can be found in almost all the cases.The hypothyroïdian dolichocolon can, according the case, be an organic dolichocolon or a functional one, the latter appearing more frequently in the light hypothyroïdy.The thyroïdine is the specific medicament of the hypothyroïdian dolichocolon and can sometimes be used with success in other forms of dolichocolon without hyperthyroïdy.