DD of rectal bleeding

Anus

- Haemorrhoids (blood after defecation)

- fissure-in-ano (+ pain)

- carcinoma

- trauma

Rectum

- carcinoma (blood streaked on stool)

- polyps

- Irradiation proctitis

- Rectal prolapse

- Solitary rectal ulcer

Colon

- Carcinoma (blood mixed with stool)

- polyps

- IBD (ulcerative colitis, crohn's diseas)

- Colonic Angiodysplasia *

- Irradiation colitis

- Ischemic colitis *

- diverticular diseases (blood alone) *

Small bowel

- meckel's diverticulum

- intussusception

- mesenteric infarction

- aortoenteric fistula

- enteritis

- leiomyoma

Upper GIT

- massive haemorrhage e.g. duodenal ulcer

Others

- anticoagulants

- bleeding diatheses

- uraemia