title: A study of intracolonic hydrogen and methane levels during colonoscopy.
abstract: Gas samples were obtained during colonoscopy for analysis. Patients were prepared with polyethylene glycol (PEG) (N = 23), phosphate enema (N = 34) and mannitol (N = 4). Air insufflation was used in all procedures. High concentrations of hydrogen were detected in 3 out of 38 gas samples in the PEG group, in 2 of 41 samples in the phosphate enema group and in one of the 8 samples in the mannitol group. All patients had a coexisting intracolonic oxygen concentration > 5%. The results suggest that potentially explosive concentrations of hydrogen may occur after conventional bowel preparations, and that insufflation of carbon dioxide during polypectomy should be a routine.
authors: Department of Gastroenterology, Mater Hospital, Dublin.
authors: E A
authors: EA
authors: Gallagher
authors: E
authors: E
authors: Clarke
authors: M
authors: M
authors: Connor
authors: I
authors: I
authors: Shanahan
authors: M R
authors: MR
authors: Smyth
authors: J R
authors: JR
authors: Lennon
authors: J
authors: J
authors: Crowe
mesh_terms: D003106:Colon / Q000378:metabolism; D003113:Colonoscopy; D004733:Enema; D005740:Gases / Q000737:chemistry*; D006801:Humans; D006859:Hydrogen / Q000032:analysis*; D008353:Mannitol / Q000008:administration & dosage; D008697:Methane / Q000032:analysis*; D010710:Phosphates / Q000008:administration & dosage; D011092:Polyethylene Glycols / Q000008:administration & dosage
chemical_list: D005740:Gases; D010710:Phosphates; D008353:Mannitol; D011092:Polyethylene Glycols; D006859:Hydrogen; D008697:Methane