The assessment of intestinal viability has for many years been an important and challenging surgical problem. The most obvious situation in which the surgeon has to make an assessment of viability is in dealing with a strangulated hernia. In fact, this lesion is becoming less frequent as a result of more widespread and early treatment of inguinal and femoral herniae. In any case, resection of doubtful or compromised bowel is now a safe and straightforward procedure. However, there are other situations in which the viability of the intestine may be of crucial importance. One thinks here of the siting of stomata and of the planning and construction of anastomoses following resections for malignant disease. Furthermore, it has been recognized in recent years that the intestine itself is subject to intrinsic diseases of its vasculature,1,2 such as are the myocardium, brain, and kidneys, though in the case of the bowel