Using a data base of 7,000 acute abdominal pains, we here described the assessed clinical manifestations of the main diseases responsible for right lower quadrant pain. However, percentages of sensibilities have been replaced by adverbs or adjectives, applying a scale of equivalence. The possible modifications of the positive predictive values have been also replaced by verbs or typical expressions. We first described the acute appendicitis syndrome (which covered congestive endoappendicitis and suppurated appendicitis) with the clinical shades or the gathered and gangrenous forms or even of the diffuse peritonitis. Features of the acute appendicitis contrast with those of the so called "non specified abdominal pains" (a new entity), and those of the subacute or chronic appendicitis. We found a good correlation between clinical and pathological findings. One of the difficulties has been to determine if a subgroup of subacute appendicitis should be or not included into the acute appendicitis.