Chancroid
Herpes Simplex Virus-2
Syphilis
Behcet's Disease
Lymphogranuloma venereum
 Granuloma inguinale (donovanosis)
Ulcerative STDs
Stercoral colitis
Ulcerative colitis
Post-infectious irritable bowel syndrome
Fibrosing colonopathy
Rectal foreign body
Trichinosis
Perianal streptococcal dermatitis