http://www.nlm.nih.gov/medlineplus/ency/article/003124.htm MedlinePlus: gases - flatulencia http://www.nlm.nih.gov/medlineplus/ency/article/003124.htm http://www.nlm.nih.gov/medlineplus/ency/article/003124.htm Gas (Medline) Medline Plus: gas NIH recommends NIH recommends http://www.nlm.nih.gov/medlineplus/ency/article/003124.htm