For the assessment of ileoanal and coloanal pouches different diagnostic tests should be applied. Apart from case history and rectal digital examination the most important methods comprise a radiologic evaluation of the pouch and its afferent loop as well as anorectal manometry for the assessment of pouch motility and sphincter function. Increasingly transanal endosonography is being used for the precise examination of size, volume, and shape of ileoanal and coloanal pouches. The afferent loop is also easily accessible to endosonography, e.g. for evaluation of bowel wall morphology and function. Furthermore, in cases of coloanal pouches following an oncologic lower anterior resection, endosonography is used in follow-up examinations for the detection of local tumor recurrence.