[Deficient lactose digestion and intolerance in a group of patients with chronic nonspecific ulcerative colitis: a controlled, double-blind, cross-over clinical trial].

Introduction: Despite the fact that the frequency of hypolactasia and lactose intolerance is similar in both chronic idiopathic ulcerative colitis patients and the general population, the elimination of dairy products from the patient's diet is a habitual recommendation. Hypolactasia is common in Mexico, but its relation to chronic idiopathic ulcerative colitis has not been established.

Aims: To evaluate lactose digestion and lactose intolerance in persons with chronic idiopathic ulcerative colitis.

Material And Methods: Thirty-nine patients with confirmed chronic idiopathic ulcerative colitis diagnosis were included in the study (mean: 31 years, range: 15 to 38). Twenty-two patients presented with rectosigmoid involvement and the remaining patients with pancolitis. No patient showed inflammatory activity according to the Truelove-Witts criteria and all consumed dairy products before diagnosis. A prospective, controlled, double-blind, cross-over study was designed. Patients randomly received 12.5 g of lactose or maltose in 250 cc water- each test 72 hours apart - and ydrogen was measured in exhaled air before disaccharide ingestion and then every 30 minutes for 3 hours. Digestion was considered deficient when there was an increase in hydrogen of at least 20 ppm. Symptom intensities were evaluated by Visual Analog Scales before, during, and after the hydrogen test. Differences between the groups were contrasted with the Mann-Whitney U and the Wilcoxon tests.

Results: Eighteen patients (46%) presented with deficient lactose digestion. No significant differences were found in the symptoms, extension, or progression of chronic idiopathic ulcerative colitis between patients that could digest and those that could not digest lactose. No patient had symptom exacerbation with the disaccharides used.

Conclusions: Lactose digestion deficiency frequency is similar in subjects with chronic idiopathic ulcerative colitis and in healthy individuals in Mexico. We do not know whether higher doses could have some effect, but symptoms in patients with inactive chronic idiopathic ulcerative colitis were not modified using 12.5 g of lactose/day.