Table 1.

Causative factors of intraabdominal free gas

Pulmonary disease	Drugs	Infectious disease
Asthma	Alpha-glucosidase inhibitor	AIDS
Chronic bronchitis	Corticosteroids	Whipple’ disease
Chronic obstructive pulmonary disease	Lactulose	Candida albicans
Positive end-expiratory pressure	Sorbitol	Clostridia
Pulmonary fibrosis	Chemotherapy agents	Escherichia coli
Gastrointestinal disorders	Gefitinib, Sorafenib, Cetuximab,	Mycobacterium tuberculosis
Pyloric stenosis	Sunitinib, imatinib, 5-FU, etc.	Intestinal parasites
Pyloric ulcer disease	Choral hydrate	Virus
Peptic ulcers	Caustic agents	Cytomegalovirus, Rotavirus,
Bowel obstruction	Mechanical causes	Adenovirus, Varicella zoster virus
Rupture of jejunal diverticula	Endoscopy	Autoimmune disease
Inflammatory bowel disease	Billiary stent perforation, Sclerotherapy	Scleroderma
Crohn’s disease, ulcerative colitis	Barium enema	Lupus variants
Adynamic ileus	Operation	Polymyositis
Appendicitis	Jejunoileal bypass, Jejunostomy tubes,	Dermatomyositis
Toxic megacolon	Post-surgical anastomosis	Sarcoidosis
Volvulus	Organ transplantation	Polyarteritis nodosa
Carcinoma	Cardiac, Bone marrow, Kidney, Liver,	Vascular disease
Hirschsprung disease	Lung, Graft versus host disease	Mesenteric vascular disease
Celiac sprue	Trauma	Intestinal infarction and ischemia
Enteritis and colitis		Intestinal ischemia
Diverticulitis		Intestinal strangulation
Emphysematous gastritis		Collagen vascular disease
Bowel necrosis