What are the causes of rectal scarring?

1. Inflammation such as perianal abscesses, ulcerative colitis, syphilis, Crohn's disease, granuloma inguinale, tuberculosis, chronic dysentery, tuberculosis, complex anal fistulas, amoebic colitis, schistosomiasis enteritis, and other conditions can lead to hyperplasia and hypertrophy of the colorectal connective tissue, forming rectal scars. Alternatively, rectal wall congestion, edema, venous and lymphatic return obstruction, and connective tissue hyperplasia can cause the intestine to lose elasticity, resulting in luminal stenosis and scar formation.

2. Surgery and improper surgical procedures. Common clinical causes include improper surgical treatment, such as excessive resection of internal hemorrhoid mucosa or external hemorrhoid skin. Over-injection or concentrated injection of sclerosing agents or necrotizing agents for internal hemorrhoids or rectal prolapse on a single plane, or excessive and large-area injection for external hemorrhoids, can also cause issues. Among these, injection therapy accounts for 37%, which is a significant proportion. Additionally, the use of corrosive drugs such as "compressed pills" in cryotherapy for hemorrhoids can cause anal canal and rectal damage, or improper rectal anastomosis can lead to scar contracture and stenosis. This is the most common clinical cause of anal canal and rectal scarring.