In 1992, the Third Geriatric Health Law was established to systematize colorectal cancer examination, so that an immune fecal occult blood test was applied to detect this type of cancer. The screening method for colorectal cancer through the immune fecal occult blood test has been improved on many times ever since, so far anticipated results being obtained in detecting cancer of the large intestine.
When it comes to the precision of a kit itself, the immune fecal occult blood test still leaves much to be desired, in practice.
This paper dwells on, why the colorectal cancer examination through the twice-screening test came to stay, while reviewing the history of chemical fecal occult blood testing in the past. Then, many unsettled problems with the colorectal cancer examination are discussed in reference to (1) the ability and method of data processing aftar close examinations, (2) the training of doctors in charge of colon endoscopic screening, (3) the way of propagating colorectal examination and (4) how to deal with detected adenomas. All these things considered. We suggest that a strategy meeting should be held for working out future colorectal cancer counterplans.

In order to know the present state of mass survey for large-bowel cancer in rural areas, we gathered the results of colorectal screening in 1989 from 45 hospitals or cancer detection center related to agricultural cooperatives of all over Japan.
In all of the 45 institutions, method of screening was fecal occult blood test, and in most of them, the stool study was immunological, of one day, and without meal restriction. Methods of further precise examination such as barium enema, total colonoscopy, sigmiodoscopy, or proctoscopy, solely or combined, were employed depending to the facilities.
The total number of examinees were 194, 834, and 8, 523 (4.4%) had a positive reaction for occult blood. Further precise examinations were performed in 4, 351 (59.7%) examinees, and 148 cases of large-bowel cancer were detected. The detective rate of cancer in total examinees was 0.08%. Among these 148 cases of colorectal cancer, 43 cases (51.8%) were in early stage. Examinees in their fifties were the most in number, and both the rate of positive reaction and the rate of cancer detection were increased as the age gets older.