ALTERATIONS IN COLONIC ANATOMY INDUCED BY CHRONIC STIMULANT LAXATIVES- THE CATHARTIC COLON REVISITED

Cathartic colon is a historic term for the anatomic alteration of the colon secondary to chronic stimulant laxative use. Because some have q uestioned whether this is a real entity, we investigated changes occur ring on barium enema in patients ingesting stimulant laxatives. Our st udy consisted of two parts. In part 1, a retrospective review of conse cutive barium enemas performed on two groups of patients with chronic constipation (group 1, stimulant laxative use [n = 29]; group 2, no st imulant laxative use [n = 26]) was presented to a radiologist who was blinded to the patient group. A data sheet containing classic descript ions of cathartic colon was completed for each study. Chronic stimulan t laxative use was defined as stimulant laxative ingestion more than t hree times per week for 1 year or longer. To confirm the findings of t he retrospective study, 18 consecutive patients who were chronic stimu lant laxative users underwent barium enema examination, and data sheet s for cathartic colon were completed by another radiologist (part 2). Colonic redundancy (group 1, 34.5%; group 2, 19.2%) and dilatation (gr oup 1, 44.8%; group 2, 23.1%) were frequent radiographic findings in b oth patient groups and were not significantly different in the two gro ups. Loss of haustral folds, however, was a common finding in group 1 (27.6%) but was not seen in group 2 (p < 0.005). Loss of haustral mark ings occurred in 15 (40.5%) of the total stimulant laxative users in t he two parts of the study and was seen in the left colon of 6 (40%) pa tients, in the right colon of 2 (13.3%) patients, in the transverse co lon of 5 (33.3%) patients, and in the entire colon of 2 (13.3%) patien ts. Loss of haustra was seen in patients chronically ingesting bisacod yl, phenolpthalein, senna, and casanthranol. We conclude that long-ter m stimulant laxative use results in anatomic changes in the colon char acterized by loss of haustral folds, a finding that suggests neuronal injury or damage to colonic longitudinal musculature caused by these a gents.