- Stasis of hardened stool in sigmoid or rectum, leading to pressure necrosis and ulceration of mucosa
- Factors contributing chronic low colonic motility and hardened stool
- Disorders limiting patient mobility (e.g. may be bed bound)
- Chronic constipation
- Neurological disorders or meds that slow colonic motility
- Blood mixed w/stool
- Sometimes lower abdominal pain (if ulcer deep, perforation)
- Chronic constipation