The Effectiveness of Transabdominal Ultrasonography in Managing Chronic Constipation in the Elderly, with a Focus on the Underlying Pathological Conditions

Chronic constipation is more common in the elderly and associated with numerous diseases. For the diagnosis of chronic constipation in the elderly, it is essential to exclude constipation secondary to colorectal cancer or other causes. Chronic constipation in the elderly also often requires lifestyle modifications, as well as drug treatments because of the involvement of pathologies such as reduced colonic transport capacity and rectal hyposensitivity. Therefore, it is extremely important to evaluate the pathophysiology of both the colon and the rectum. Transabdominal ultrasonography (TUS) is a key technique for providing comprehensive medical care and allows simultaneous functional assessment and exclusion of organic diseases related to constipation such as colorectal cancer. Although several studies have reported the clinical utility of TUS for chronic constipation, which includes its simplicity, noninvasiveness, and low cost, the majority were in children. Thus, there are limited studies in adults. Herein, we review the utility of TUS for indirect assessment of colonic transit time using several TUS parameters that can be applied clinically, as well as treatment options for chronic constipation. The constipation index (i.e., mean transverse diameter of the colon), assessed by TUS, is a useful indirect indicator of colonic transit time. If the constipation index is <21.2, increased fiber or treatment with osmotic agents should be used. If the constipation index is ≥21.2, then the ratio of the left to the right lateral colonic diameters should be evaluated. If this value is ≥0.5, a secretagogue or bile acid transporter inhibitor should be administered. It is noteworthy that nursing care is becoming increasingly important in Japan’s super-aging society. A significant proportion of nursing care is provided to patients with chronic constipation, a cohort that is predicted to grow in the future. In these patients, fecal masses often remain in the rectum, which may require an enema or stool extraction. Therefore, it is important to assess both the presence of feces in the rectum and the consistency of the feces. Recently, portable ultrasound (US) devices equipped with artificial intelligence have been developed and used clinically for treatment of patients with chronic constipation in nursing care. Rectal findings using portable US devices can aid in selecting appropriate constipation treatments. Thus, portable US will likely become increasingly important as a next-generation examination device in nursing care. TUS (including portable US) is noninvasive, simple, and repeatable and will become a fundamental modality in the management of chronic constipation.