I can't release gas while sitting on a chair or bed. while standing i have got to make an effort to release gas. what this problem is called?

Motility problem: Since gas depends on intestinal movement, anything that slows the intestine may make it harder to pas gas. Examples of this problem are irritable bowel syndrome/constipation predominant; taking medications that slow the gut, such as Lomotil, (diphenoxylat and atropine) Elavil, and Atropine; or bowel damage from chronic laxative use.