Table 2.

Causes of free perforation of the small bowel

Immune-mediated or inflammatory

Crohn’s disease (CD)

Celiac disease or gluten-sensitive enteropathy (GSE)

Collagenous sprue

Graft-vs-host disease (GVHD)

Infections

Viral: Cytomegalovirus (CMV)

Bacteria: Salmonella paratyphi, mycobacterium tuberculosis

Parasites: Ascaris lumbricoides

Protozoa: Entameba histolytica

Drugs and biological agents

NSAIDs: Indomethacin

Enteric-coated potassium chloride

Chemotherapy (?steroids)

Monoclonal antibodies: Bevicuzimab

Congenital

Meckel’s diverticulum

Jejunal or ileal duplications

Metabolic

Homocystinuria

Vascular

Wegener’s granulomatosis

Giant cell arteritis

Allergic granulomatous arteritis (i.e., Churg-Strauss syndrome)

Henoch-schonlein purpura

Buerger’s disease

Atherosclerotic vascular occlusion

Radiation-induced vascular injury

Neoplasm

Primary (adenocarcinoma, EATCL, angiosarcoma)

Secondary (melanoma, breast, mesothelioma, lung)

NSAIDs: Non-steroidal anti-inflammatory drugs.