Although exploratory incision for the purpose of making a diagnosis is, as a rule, undesirable, in certain cases the operation is not only justifiable but strongly to be urged. Whenever cancer of the stomach is suspected and the diagnosis cannot be verified by ordinary methods, an exploratory operation should be urged, for it has been clearly proved that in the surgical treatment of cancer the earlier an operation can be performed the greater will be the chance of radical cure, whereas if a diagnosis of the disease be not made until a tumour can be felt by palpation, it is, as a rule, too late for radical treatment.

An exploratory operation may also be required in certain cases of palpable tumour of the stomach in which it is just possible that the growth may be amenable to surgical treatment, but where it cannot be said beforehand whether the lymphatic glands are too extensively involved, or the disease has so far invaded the adjoining tissues that removal of the growth would be useless, when a gastroenterostomy or a jejunostomy may have to be performed as palliative procedures.

In some other diseases and injuries of the stomach it is found impossible to say what operation or operations may be required before the abdomen is opened and the extent and nature of the disease ascertained by inspection and palpation. Every operation on the stomach therefore, in this sense, is an exploratory procedure, and the surgeon must be prepared to adapt himself to circumstances when he sees the nature and extent of the disease.