After a two-week basal period, 24 patients were randomly allocated to receive, with a crossover double-blind design, for two consecutive four-week periods, bran (20 g/24 hr) or placebo. The daily intake of water and dietary fibers was standardized. Symptomatology, oroanal transit time, bowel frequency, and stool weight were assessed in basal conditions and at week 4 and 8 of the treatment. Oroanal transit time decreased and bowel frequency and stool weight increased significantly during both bran and placebo administration in comparison with basal period. Bran treatment was more effective than placebo in improving bowel frequency and oroanal transit. During bran treatment oroanal transit time became normal only in patients with slow colonic transit and not in those with slow rectal transit. Neither the occurrence nor the severity of the most frequent accompanying symptoms of chronic constipation differed significantly between placebo and bran treatments.

In patients with constipation the prevalence of melanosis in rectal biopsies was evaluated in an attempt to correlate its occurrence with laxative consumption and intestinal stasis. Melanosis was present in 58 percent of the patients and in none of a control group. Melanosis was present in 73.4 percent of patients consuming anthracene laxatives and in 26.6 percent of those not consuming anthracene laxatives (P less than 0.01). No correlation was found between the occurrence (and grading) of melanosis and pattern of transit through the large bowel, bowel movements, and duration of symptoms. Results of this study seem to indicate that intestinal stasis is not a cause of melanosis of the colon and rectum and confirm that melanosis may well be due only to the consumption of anthracene laxatives; melanosis coli does not appear to be a sensitive marker of impairment of motor function in the "cathartic colon."

Idiopathic achalasia is a rare disorder of the oesophagus of unknown aetio-pathogenesis characterized by a myenteric inflammation, aperistalsis and insufficient lower oesophageal sphincter relaxation. Vasoactive intestinal peptide (VIP), present in the myenteric plexus, is involved in smooth muscle relaxation and acts as an anti-inflammatory cytokine. The human VIP receptor 1 gene (VIPR1) is highly polymorphic and may play a role in idiopathic achalasia. One hundred and four consecutive patients and 300 random controls from the same geographic area were typed for five SNPs mapping in the VIPR1 gene. Patients with idiopathic achalasia show a significant difference in allele, genotype and phenotype distribution of SNP rs437876 mapping in intron 4. This association, however, was almost entirely due to the group of patients with late disease onset (P = 0.0005). These results strongly suggest that idiopathic achalasia is a heterogeneous disease with a different aetiology in cases with early or late disease onset.

No abstract

Rectal sensitivity is often reduced in patients affected by chronic constipation, but it is not known whether this alteration differs according to the severity and the site(s) of the slowing of gastrointestinal transit. Moreover, it is not known whether alteration precedes or follows bowel complaints. In this study, perception of intrarectal distension was evaluated in 28 healthy controls, in 20 patients complaining of constipation and with a normal gastrointestinal transit time (less than 96 hr), and in 44 patients complaining of constipation and with a prolonged gastrointestinal transit time (greater than 96 hr). Within the latter group, perception to intrarectal distension was analyzed in patients with slowing of transit in the rectum only, in the colon only, and in both the rectum and the colon. In a subgroup of 22 patients, rectal sensitivity was evaluated before and after treatment. Rectal sensitivity was found to be reduced significantly in constipated patients; it was more severely reduced in patients with objective evidence of prolonged gastrointestinal transit time and with slow transit in the rectum. Rectal sensitivity improved in patients who responded to treatment and did not vary significantly in nonresponders.