Inflammatory bowel disease (IBD) can be a debilitating condition to live with, yet it is largely invisible to all but the afflicted individual. The condition has two main forms — Crohn's disease and ulcerative colitis (see page S98). And because it emerged only in the past 150 years, it is considered to be a relatively new disease. Nowhere is this more true than in Asia, where cases of IBD have soared in recent decades (S100). The reasons for this rise are unclear, but theories about the environmental factors that drive IBD abound, including one that suggests the pursuit of cleanliness and the subsequent loss of intestinal worms may have played a part (S103).
In most cases, genes are thought to have a minor role. But genetic studies are providing insight into the biological mechanisms behind the disease, which may be targets for future therapies (S104). There is a subset of patients in whom all drugs fail. Cell-based therapies may offer a much needed alternative, although regenerative approaches to IBD have attracted controversy (S106). Transplants of faecal matter from healthy donors are also being explored — such treatments have worked wonders for antibiotic-resistant infections, but despite patient interest, evidence of a benefit for IBD is proving elusive (S109).
Mental health problems concurrent with IBD are common, and are another opportunity for treatment (S113). Better support, understanding and openness will help people to live with IBD, and social media is providing patient advocates with a way to make this happen. But does what they do have a clinical impact? A new Nature Video finds out (see go.nature.com/ibd-video).
We thank the editors of Nature Reviews Gastroenterology and Hepatology for their help with this Outlook.
We are also pleased to acknowledge the financial support of Salix Pharmaceuticals in producing this Outlook. As always, Nature has sole responsibility for all editorial content.