How is anal fistula formed? Can diarrhea also lead to anal fistula?

It is generally believed that anal fistula is the sequela of perianal abscess, and 95% of perianal abscess is caused by anal gland infection, which can be caused by the following reasons:

1. Perianal abscess: The main cause of anal fistula is anal adenitis caused by contaminated feces staying in anal recess.

2, anorectal injury: trauma, bone foreign bodies from the digestive tract, metal, anal surface and anoscopy damage the anorectal, bacteria invading the wound can cause perianal abscess.

Anal fissure: Repeated infection of anal fissure can cause subcutaneous fistula and anal adenitis.

4. Private surgery: internal hemorrhoid injection is too deep or postoperative infection, postpartum perineal suture infection, prostate and urethral surgery infection, etc. Can spread to anus and rectum to cause abscess and fistula.

5, tuberculosis: swallowing bacteria or a small amount of blood-borne infection can cause tuberculous anal fistula.

6, ulcerative colitis: can cause anal fistula.

Crohn's disease: may be accompanied by anal fistula.

8, anorectal cancer: often accompanied by anal fistula.

9. Blood-borne infections: such as diabetes, leukemia and aplastic anemia. Anal fistula can often be caused by blood-borne infection due to the decrease of body resistance.

Others: lymphogranuloma, actinomycosis, sacrococcygeal osteomyelitis, diverticulitis of rectum and sigmoid colon can also cause perianal abscess and anal fistula.