Experimental colonic carcinogenesis after gastric surgery

Peptic ulcer surgery may predispose to the subsequent development of colorectal cancer. This experimental study has investigated the effects of gastric operations on colonic cell proliferation, bile acid excretion and carcinogenesis. Male Sprague‐Dawley rats (n = 705) underwent sham operation, Polya partial gastrectomy or vagotomy and pyloroplasty. The carcinogen azoxymethane was administered weekly for 6 weeks thereafter (total dose 60 mg kg−1). When the animals were killed 24 weeks after operation, colons were examined for mucosal mass, crypt cell production rate (CCPR) and tumour yield; faeces were assayed for contents of neutral steroids and bile acids (both total and individual). Morphometric indices and mucosal DNA content were similar in all three groups. Polya gastrectomy reduced: (1) CCPR throughout the colon (by 42–65 per cent, P< 0·002); (2) the number of rats with colorectal tumours (26 per cent versus 63 per cent, P