The defecation control with an aid of purgative was performed to 87 % senile tenants in an elderly nursing home in Tokyo, Japan. The diarrhea associated with side effects was noticed to pose a serious problem. Due to consumption of soft food⁄ mousse, the natural defecation could not be performed to the elderly senile person therefore a purging medicine (purgative) is normally required to stimulates evacuation of the bowels. Such a necessity of an abnormal evacuation could be caused by an insufficient daily intake of dietary fiber and referred to be constipated.   In attempt to bring remedy to natural defecation, 10. 5g of partially hydrolyzed guar gum (PHGG), a soluble dietary fiber which has been well known for a number of physiological effects, supplemented to yogurt was fed to 21 elderly senile subjects (One male and 20 females, and average age±SEM : 86. 3±10. 9 years). The fecal were collected and characterized to assess the influence of amount of purgative ingested during study and compared to condition when ingestion of PHGG was discontinued.   Results revealed that although fecal frequency was 5. 3 times⁄ week during the period of PHGG ingestion, it decreased in 4. 8 times ⁄ week for the 3rd month when the ingestion of PHGG was discontinued. Moreover, while the number of times when there was no defecation was 1. 3 times⁄week during the PHGG ingestion period, however for the 3rd month it was 1. 8 times⁄week after discontinuation of PHGG ingestion. In addition, frequency of purgative administration during the PHGG ingestion period was 0. 3 times⁄week while it became 0. 6 times ⁄three months after discontinuation of PHGG ingestion.   Aforementioned results clearly suggest that PHGG is effective in reduction of diarrheal fecal for elderly senile person to help remedy normalize to natural defecationeven after a reduction⁄ discontinuation of a purgative aid.