Constipation: This is often the most common cause of gaseous distention in the colon, including the right colon, due to the accumulation of gas and feces. The right colon is more prone to distention because it is a common site for gas accumulation due to its anatomy and the type of contents it typically holds.

Irritable Bowel Syndrome (IBS): Characterized by abdominal pain, bloating, and changes in bowel movements, IBS can lead to gaseous distention of the colon, including the right side.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause inflammation and lead to distention of the colon.
Diverticulitis: Inflammation of the diverticula in the colon wall can cause distention, especially if the affected area is in the right colon.

Intestinal Obstruction: A mechanical blockage of the intestine can lead to severe distention and is a medical emergency. Early diagnosis is crucial to prevent complications like ischemia and perforation.
Toxic Megacolon: A life-threatening condition characterized by a very inflated colon, which can occur in the context of severe colitis or other conditions. It requires immediate medical attention.
Ischemic Colitis: Reduced blood flow to the colon can cause distention, pain, and potentially severe complications if not promptly addressed.

Hirschsprung's Disease: A congenital condition affecting the colon's ability to move stool, leading to severe constipation and distention. It's more commonly diagnosed in infancy but can be missed and present later in life.
Colonic Volvulus: A twisting of a portion of the colon that can cut off blood supply and lead to distention. It's less common but requires urgent treatment to prevent tissue death.
Chagas Disease: Caused by a parasite, it can lead to megacolon, a condition characterized by an abnormally enlarged colon, which might present with gaseous distention. It's rare in many parts of the world but more common in certain endemic areas.