Retrograde spread of mesalazine (5-aminosalicylic acid)-containing enema in patients with ulcerative colitis.

In order to investigate the retrograde spread in the colon and its relationship to the extent of the diseased area, the authors evaluated a 100ml enema of mesalazine (5-aminosalicylic acid, Pentasa') lg in a consecutive series of 30 patients with ulcerative colitis. The enema was labelled with 10 MBq 99mtechnetium-human serum albumin microcolloid. Sequential scintigraphic imaging was performed in all patients, and the results compared with the extension of the disease as found by colonoscopy. If the enema reached the entire affected area it was interpreted as 'topically adequate'. In 80% of the patients there was retrograde spread of the enema beyond the rectosigmoid, thus reaching the affected area in ulcerative colitis. No relationship was found between the extent of dispersion of the enema and the time of defecation prior to scintigraphy. The authors conclude that a 100ml 'Pentasa' enema may be adequate for treatment of ulcerative colitis extending up to the splenic flexure.