Assessment of rectal feces storage condition by a point-of-care pocket-size ultrasound device for healthy adult subjects: A preliminary study.

The aim of this study was to assess rectal feces storage condition by a pocket-size ultrasonography (PUS) in healthy adults so as to define normal rectal defecation desire. Participants were first assessed rectum by PUS imaging immediately after defecation desire (pre-defecation). Nurses checked the amount and quality of the participants' feces using King's Stool Chart and Bristol stool scale. Finally, PUS was performed for defecation with no defecation desire (post-defecation). Pre-defecation PUS detected high echo area in all patients. All of the post-defecation PUS did not detect high echo area (perfectly no recognizable high echo area in 54.5%, high echo line in 36.4%, and low echo of entire circumference in 9.1% of the patients). Average diameter of rectal crescent was 4.22 ± 0.8 cm. Bristol Stool Scale 1 or 2 (indicating hard stool) of pre-defecation PUS indicated high echo area and acoustic shadow in 100% of the patients. This study showed that healthy adult with defecation desire had high average rectal echo area of 4.0 cm in diameter. PUS may be able to define the rectum diameter for defecation desire of elderly people. PUS is capable of assessing fecal retention of the rectum for point-of-care examinations in home care.