Bidet-toilet Use as a Cause of Anterior Aphtoid Ulcer in the Anorectum

Abstract

Electric bidet toilets are automatic devices that deliver water jets to clean the anus. Although the use of bidets to clean the anus after defecation contributes to hand hygiene and local comfort, excessive use may cause anal pruritus and incontinence. However, no cases of anorectal aphtoid ulcers caused by bidet use have yet been reported in literature. A 61-year-old woman presented to our hospital with anal bleeding and pain. Anoscopy revealed an aphtoid ulcer in the anterior midline anorectum. She reported using a bidet toilet and washing her anus before and after defecation for one year. The frequency of washing was five times or more per day, the force of the water jet was strong, the thickness of the water was thin, and the duration of washing per use was 1 min or more. She responded well to the advice of stopping bidet use. At the follow-up, 5 weeks after discontinuing bidet use, she became asymptomatic, and the anoscope showed that the aphtoid ulcer had completely healed. The water jet of the bidet toilet seemed to be the causative factor for the anterior aphtoid ulcer in the anorectum.

Introduction

Electric bidet toilets are automatic devices that deliver water jets to clean the anus after defecation. Bidet toilets are widely used in Japan, and in March 2021, their diffusion rate in house-holds was 80.3%, according to the Cabinet Office's Consumer Trend Survey[1]. Bidets have been developed to incorporate different functions to improve user comfort and today, users can select their preferred force, thickness (narrow or wide), and temperature of the water jet. Cleaning the anus after defecation using bidets contributes to hand hygiene and local comfort, and may be effective against constipation. However, excessive bidet use can cause anal pruritus and anal incontinence[2,3]. Furthermore, its use may lead to anorectal ulcers. A written consent has been obtained from the patient to publish the information, including photographs.

Case Report

A 61-year-old woman presented with anal bleeding and pain for 2 weeks. She had a 2-year medical history of chronic cardiac and respiratory failure. She had undergone Delorme's procedure for rectal prolapse 9 months prior. Digital examination revealed anal pain, and an anoscope showed an aphtoid ulcer in the anterior midline anorectum that was associated with hemorrhage (Figure 1). She had no evidence of recurrent rectal prolapse and had neither a feeling of prolapse nor fecal incontinence. Fibrosis or visible internal anal sphincter in the ulcer, hypertrophic papilla proximal to the ulcer, or sentinel pile distal to the ulcer was not observed. On taking a detailed history, she reported using a bidet toilet and washing the anus before, partly to aid defecation, and after defecation for one year because she had experienced a difficulty with evacuation. The frequency of washing was five times or more per day, the force of the water jet was strong, the thickness of the water was thin, and the duration of washing per use was 1 min or more (range: 1−3 min). She was recommended to stop bidet use but was not otherwise treated with topical medication or laxatives. She responded well to the advice and became asymptomatic within 3 weeks. At the follow-up, 5 weeks after discontinuing bidet use, the anoscope showed that the aphtoid ulcer had completely healed (Figure 2).

Figure 1.

Aphtoid ulcer with a blood point in the anterior anorectum.

Figure 2.

Aphtoid ulcer was completely healed 5 weeks after discontinuing bidet use.

Discussion

This is the first study to indicate the water jet of the bidet toilet as the causative factor of anterior aphtoid ulcers in the anorectum. Our patient used the bidet before and after defecation and washed the anus with a strong and thin water jet for one minute or more; she repeatedly cleaned the anus several times a day. Active use of the bidet may cause traumatic injury to the anterior anorectum. Once a traumatic ulcer develops, repeated daily injury by the same mechanism impairs healing and may even worsen it. She had difficulty with evacuation and used a bidet before defecation as a defecation aid in a manner similar to an enema, with water penetrating the rectum. Garg[4] reported on ten patients with anterior fissures in ano, which might have been caused by the strong water jet. These patients had typical pathological features of a chronic anal fissure at the lower anal canal, which included fibrosis at the base of the fissure, visible internal anal sphincter, a hypertrophic papilla proximal to the fissure, or a sentinel tag distal to the fissure. In contrast, our patient had an irregular aphtoid ulcer in the anterior midline anorectum without hypertrophic papilla or sentinel tag. Because she had a history of rectal prolapse and had a lax anal sphincter, the upper anal canal or lower rectum might have been hit easily by the water jet of the bidet. The differential diagnoses included Crohn's disease, carcinoma, syphilis, tuberculosis, and HIV infection, but our patient had no indication of these diseases. Excessive anal washing with bidets potentially causes anal symptoms such as anal pruritus, anal incontinence, or anorectal traumatic ulcer. In the present writer's clinic, anal cleaning is specifically restricted to less than 5 s with weak water pressure and a wide water jet. There is a possibility of trauma caused by wiping the anus with paper after washing the anus. However, as the ulcer healed simply after discontinuing bidet use, it is probable that the aphtoid ulcer developed due to the excessive use of the bidet.

Conflicts of Interest

There are no conflicts of interest.

Author Contributions

Akira Tsunoda: drafting of the article, and final approval of the version to be published.

Approval by Institutional Review Board (IRB)

Ethical Committee of Kameda Medical Center

Review board approval number: 22-029