IBS is an abbreviation with several meanings:
* Irritable bowel syndrome, a disorder of the bowel <-----Is this it?
* IBS, a satirical news channel on the BBC's programme Broken News
* ICFAI Business School, an MBA School in India
* Institute of Broadcast Sound, a UK broadcasting professional association
* INTELSAT business service, a satellite communication standard provided by INTELSAT
* Intercollegiate Broadcasting System - serves college/community radio stations, streaming webcasters, etc.
* International Bible Society, a group that translates and publishes the Bible with the intent of Christian proselytization
* International Bank Services Inc., an investment bank
* International Biogeography Society, a society for the study of biogeography
* International Biometric Society, an academic statistical association for mathematical and statistical methods in the biosciences
* Internet Broadcasting, a web design firm focused on broadcast television
* Intrabeam Scattering, a collective effect arising in high-intensity particle beams
* Intelligent Building Solutions, an automation company
* IBS Software Services, an airline, cargo, Logistics products and services company
* Identical by State, a genetic term also known as non-identical by type (NIBT)
* International Builders' Show, an annual trade show organized by the National Association of Home Builders
* Indiana Boys School, a former name of Plainfield Juvenile Correctional Facility
* Instytutu Badań Strukturalnych, the Institute for Structural Research