Colonic pH: a comparison between patients with colostomies due to trauma and colorectal cancer.

Colonic pH is important in the regulation of colonic cell growth, control of absorption and secretion, and bile acid degradation, which may be a key step in the development of colon cancer. This study determined the mucosal, luminal, and fecal pH in right and left colons of otherwise healthy patients who underwent colostomies because of trauma. The pH was evaluated while patients consumed a western diet. In addition, the mucosal, luminal, and fecal pH in patients with colostomies carried out for colorectal cancer also was assessed. All patients were blacks--a low-risk group for colorectal cancer. The results showed that mucosal pH was alkaline (pH 8) and was similar on both sides of the colon of healthy colostomates and in colon cancer patients. Luminal pH (7.6) was the same in healthy right colostomates and cancer patients and was significantly lower that mucosal pH. Fecal pH was significantly lower in right colostomates (6.0) than in left (6.5), and in healthy right colostomates compared with colon cancer patients (6.6). In addition, fecal pH was significantly lower than mucosal and luminal pH.