Why does the anus itch after a bowel movement?

Anal itching after defecation may be caused by improper cleaning, dietary irritation, anal eczema, hemorrhoids, enterobiasis, and other factors. Management can be based on the specific situation. It is recommended to visit a hospital promptly and follow medical advice for treatment.

1. Improper cleaning: If fecal residue remains after defecation due to inadequate wiping, it can irritate the skin around the anus and cause itching. After each bowel movement, gently wipe the anal area from front to back with soft toilet paper. If possible, washing the anus with warm water is better to maintain cleanliness and dryness.

2. Dietary irritation: Excessive consumption of spicy foods such as chili peppers and Sichuan peppercorns, or alcohol consumption, can stimulate the intestines. During defecation, blood vessels around the anus may dilate, causing itching. It is recommended to adjust dietary habits by reducing intake of spicy foods and alcohol, and increase consumption of foods rich in dietary fiber.

3. Anal eczema: Caused by various internal and external factors, such as localized dampness or allergies, anal eczema can lead to red patches, papules, and blisters on the skin around the anus, accompanied by severe itching. Scratching may lead to erosion and exudation. Patients can use calamine lotion, mometasone furoate cream, loratadine tablets, or other medications under medical guidance to alleviate symptoms.

4. Hemorrhoids: Hemorrhoids occur due to congestion or blood stasis and swelling of the venous plexus in the rectum or anal canal. During defecation, irritation of the hemorrhoidal mass may increase secretions, irritating the skin around the anus and causing itching, often accompanied by rectal bleeding, pain, and prolapse of masses. Patients are advised to use Ma Ying Long Musk Hemorrhoid Ointment, Huazhi suppository, Sophora fruit pill, or other medications under medical guidance to relieve discomfort.

5. Enterobiasis: This condition mainly occurs due to accidental ingestion of pinworm eggs, which hatch into adult worms in the intestines. Female worms crawl out of the anus at night to lay eggs, irritating the anal skin and causing itching. It is commonly seen in children and often occurs at night, accompanied by symptoms such as restless sleep and teeth grinding. Patients can take medications such as albendazole tablets, mebendazole tablets, or pinworm ointment as directed by a physician to alleviate symptoms.

In daily life, it is also important to change underwear frequently and choose cotton underwear with good breathability to reduce bacterial growth.

References:

[1] Li Yangchun. How Traditional Chinese Medicine Treats Hemorrhoids[J]. Everyone's Health, 2025, (02): 76-77.

[2] Zhao Ying, Zhang Qiao, Li Chungeng, et al. Study on the Effect of Micro-Needling Ear Acupuncture Combined with Emotional Intervention in TCM on Sleep Quality and Emotional Status of Patients with Anal Eczema[J]. Hebei Journal of Traditional Chinese Medicine, 2024, 46(01): 91-94+98.