The gastrointestinal market has traditionally split into two categories: the heartburn diseases GERD and ulcer, and "other." The former category has yielded blockbuster successes for several large companies, including SmithKline Beecham and AstraZeneca. Those markets have plateaued, however, and now companies are casting about for follow-on products in GI. Large companies and small companies have begun to venture into the "other" GI diseases, irritable bowel syndrome, and inflammatory bowel disease. These diseases are all difficult to diagnose, and the mechanisms that underpin them are still unknown. Furthermore, the diseases are multi-factorial, immunological inflammatory diseases and drug discovery is challenging. While waiting for new drugs, many small companies find the market controlled by 10,000 gastroenterologists in the US to be a niche opportunity that represents a large market that can be targeted with a small salesforce. Device companies too have a role to play, in giving gastros new procedures that keep patients in their franchise, which is encroached upon by GPs and general surgeons.