A number of other problems may cause symptoms similar to those of irritable bowel syndrome (IBS), including:

• Abuse of laxatives or antacids.
• Use of sorbitol or other artificial sweeteners.
• Lactose intolerance.
• Inflammatory bowel disease.
• Malabsorption syndrome, such as celiac disease.
• Tumors of the digestive system.
• Problems with the pancreas.
• Parasitic infestation, especially in people who have traveled to areas with poor sanitation.
• Thyroid disease.
• Diverticulitis.
• Diseases of the female reproductive organs, such as endometriosis.
• Gallstones.
• Gastroesophageal reflux disease (GERD).