... mineral spring water, and for horse racing 640 the treatment of hepatic encephalopathy (see Chapter 33) Osmotic laxatives are frequently used to clear the colon for diagnostic procedures or surgery ... bacteria including Shigella and Salmonella spp, viruses including the Norwalk family, and parasites (particularly Giardia lamblia) have also been implicated Recognition that transmission is almost ... abdominal pain, although there is little objective evidence for their efficacy from controlled clinical trials The generation of evidence is complicated by the variable nature of IBS symptoms,...