Citations

Chronic constipation is a highly prevalent disorder that affects approximately 15% of the US population. Chronic constipation refers to patients who have had symptoms for more than 6 months. In clinical practice, chronic constipation is often used interchangeably with the term functional constipation. This is best defined using the Rome III criteria, which involves an evaluation of stool frequency in addition to symptoms of straining, feelings of incomplete evacuation, and the need to use manual maneuvers to assist with stool evacuation. Symptoms can be burdensome, leading to a reduction in patients’ quality of life. As a national healthcare issue, chronic constipation is also important because it imposes a significant economic impact on the healthcare system. A number of treatment options are currently available, both over-the-counter and by prescription, although not all patients respond to these therapies. This review will focus on new medical treatment options for the management of chronic constipation, and the safety and efficacy of these agents will be reviewed. In addition, the efficacy of new diagnostic tests to evaluate colonic motility and anorectal function are described.

Recent evidence suggests that the microbial community in the human intestine may play an important role in the pathogenesis of obesity. We examined 184,094 sequences of microbial 16S rRNA genes from PCR amplicons by using the 454 pyrosequencing technology to compare the microbial community structures of 9 individuals, 3 in each of the categories of normal weight, morbidly obese, and post-gastric-bypass surgery. Phylogenetic analysis demonstrated that although the Bacteria in the human intestinal community were highly diverse, they fell mainly into 6 bacterial divisions that had distinct differences in the 3 study groups. Specifically, Firmicutes were dominant in normal-weight and obese individuals but significantly decreased in post-gastric-bypass individuals, who had a proportional increase of Gammaproteobacteria . Numbers of the H 2 -producing Prevotellaceae were highly enriched in the obese individuals. Unlike the highly diverse Bacteria , the Archaea comprised mainly members of the order Methanobacteriales , which are H 2 -oxidizing methanogens. Using real-time PCR, we detected significantly higher numbers of H 2 -utilizing methanogenic Archaea in obese individuals than in normal-weight or post-gastric-bypass individuals. The coexistence of H 2 -producing bacteria with relatively high numbers of H 2 -utilizing methanogenic Archaea in the gastrointestinal tract of obese individuals leads to the hypothesis that interspecies H 2 transfer between bacterial and archaeal species is an important mechanism for increasing energy uptake by the human large intestine in obese persons. The large bacterial population shift seen in the post-gastric-bypass individuals may reflect the double impact of the gut alteration caused by the surgical procedure and the consequent changes in food ingestion and digestion.