The cause of irritable bowel syndrome is unknown; however, many health experts conclude that miscommunication between the intestinal tract and the brain is a primary cause, according to WebMD. When miscommunication occurs, abnormal spasms or muscle contractions can cause cramping pain that affects the bowels.
Abnormal muscle contractions or spasms may ultimately cause diarrhea by speeding up the passage of stool, explains WebMD. In addition, the spasms can slow down the passage of stool which leads to bloating or constipation. Some people may have sensitive intestines, causing common IBS symptoms.
Irritable bowel syndrome may also be caused by factors that affect the intestines, according to WebMD. For example, eating habits can irritate the intestines, although health experts have not identified specific foods linked with irritable bowel syndrome. Medications or antibiotics may also cause a sensitive intestinal tract to spasm. An infection in the digestive tract can lead to extreme constipation or diarrhea as well as hormonal changes during a menstrual cycle or menopause.
People with anxiety, depression, stress and psychological issues may be more prone to irritable bowel syndrome, explains WebMD. In addition, genetics may also play a role in contracting the illness. People with a family history of the syndrome may be more at risk for developing irritable bowel syndrome.