[Irritated bowel syndrome: clinico-morphological types]

One hundred twenty eight patients with irritated bowel syndrome (IBS) were included in the study and divided into two equal groups. Group one consisted of patients with type II IBS (without atrophic changes in the colon mucosa, CM); group II consisted of patients with type II IBS (with atrophic changes in the CM); the control group consisted of 24 practically healthy individuals. All the subjects, including the healthy ones, were examined using clinical, endoscopic, immunohistochemical methods, and electron microscopy. The study found that the development of type IIBS was connected with hyperplasia and hyperfunction of serotonin-producing cells with intensification of apoptosis. The number of colonocytes with nuclei that are immunopositive to D1 cycline increases, and the number of colonocyte nuclei that are immunopositive to proliferating cell nuclear antigen decreases. The onset of type II IBS is associated with hyperplasia and hyperfunction of all apudocyte populations, including those producing melatonin and serotonin, and simultaneous reduction of the number and functional exhaustion of VIP-producing and mast cells. Colonocyte apoptosis intensifies; their proliferative potential decreases.