The clinical picture and diagnosis of pathological conditions of the epiploic appendage of the colon (torsion, inflammation, necrosis) are discussed from analysis of the literature data and 180 cases from the author's practice. The pain syndrome is described in detail. The author identified the mechanisms of the development of localized rigidity of the muscles of the anterior abdominal wall and described two new characteristic symptoms of this disease: (1) pain appearing or intensifying when the abdomen is thrust forward and in mild tapping on the healthy side of the anterior abdominal wall with the finger tips; (2) the appearance of intensification of pain when the skin fold on the abdomen is pulled upwards. These symptoms were tested in 17 patients and proved to be positive in all of them.