In my three cases of intestinal infantilism, the kreatinin excretion was more irregular than normally, and the kreatinin coefficient was low. Kreatin was found in the urine on a kreatin-free diet. The sum of kreatinin and kreatin was also irregular.
The endogenous uric acid was irregular from day to day.
The kreatin excretion is apparently lower on a high fat diet than on a high carbohydrate diet.