The American College of Gastroenterology publishes an email newsletter with useful and interesting information for IBS and IBD sufferers. Here is a link to sign up for their excellent newsletter:
The same group has posted a glossary of GI-related terms, which can come in handy if, say, you've forgotten the definition of Percutaneous transhepatic cholangiography. They also cover all the more common terms...
Here is their section on abdominal pain syndrome: http://patients.gi.org/topics/abdominal-pain/
And one on IBS: http://patients.gi.org/topics/irritable-bowel-syndrome/
Groups and Organizations
The IBS Self Help and Support Group has over 50,000 members http://www.ibsgroup.org
LinkedIn has several IBD groups, "IBD - Crohn's Disease & Ulcerative Colitis - CCF" the "IBD Research Foundation" and "Crohn's, Colitis & Digestive Disease Support Network". There isn't much on LinkedIn for IBS however.
DailyStrength has an IBS support group here
IBS Network, formerly "The Gut Trust", is a British group offering support for a fee. Be careful, they spell some words funny.