In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

1. Two normal subjects and ten patients with chronic renal failure were given 15 or 20 g of calcium carbonate in the morning and 5·6 or 8·4 g of calcium phosphate in the evening for 13-41 days.2. During the high calcium and phosphate intake there was a rise in calcium and phosphate absorption from the gut in the normal subjects and to about the same extent in the patients with chronic renal failure.3. The calcium and phosphate balances became positive while there was a rise in plasma calcium and a fall in plasma phosphate. There was also a fall in urinary phosphate excretion.

SUMMARY We compared the rectal microflora of 16 patients with surgically excluded colorectum with 16 healthy controls. The cause of diversion was inflammatory bowel disease (n=10), colon cancer (n=3), miscellaneous (n=3). Six patients had a diversion colitis. In the excluded colorectum, the total bacterial count was only slightly lower than controls but the variety of the flora was significantly reduced. This reduction was confined to strict anaerobes, mainly the genus Eubacterium and Bifidobacterium. Among aerobes, enterobacteria were more often isolated than in controls. This altered microflora of excluded colorectum could be involved in the mucosal damage observed in some cases.Human colon contains an unique microbial ecosystem composed by a large variety of bacteria mainly strict anaerobes.' The substrates for the microbial development are both exogenous (food residues not digested by human enzymes) and endogenous (such as bile and mucus).'2Beneficial effects of the microflora on host are resistant to colonisation3 and the formation of short chain fatty acids, substrates for the colonocytes.4In patients undergoing colostomy the remaining colon and rectal segment are completely isolated from the upper gastrointestinal tract. Diversion of the faecal stream may be associated with diversion colitis.5 Although, the pathophysiology of this disorder is unknown, the bacterial flora might be implicated either by implantation of harmful strains or by partial loss of the normal colonic microflora.6 Only scarce information exists, however, about the bacterial population of excluded colons.7 The aim of the present study was to determine the microflora of excluded colon in 16 patients operated on for various colonic disease. Methods PATIENTSThe clinical data of the 16 patients are summarised in

No abstract

. Serum levels, half‐lives and urine concentrations of cephalexin, an oral cephalosporin antibiotic which is unique in its absorption and excretion, are reported in human volunteers, fasting, non‐fasting and non‐fasting plus probenecid. Accumulation does not seem to occur. . Cephalexin clearance was 376 ml./min and the ratio of cephalexin/creatinine clearances was 2·6 in one volunteer. . Cephalexin had no effect on the urinary excretion of leucocytes, red cells or protein. . The very high rate of absorption giving high serum levels and urine concentrations suggest cephalexin will be a useful antibiotic in susceptible bacterial infections in man.