Common bowel disorders include:

• irritable bowel syndrome (IBS)
• Crohn’s disease
• celiac disease
• intestinal obstruction

Irritable bowel syndrome (IBS) is a problem that affects the large intestine. It can cause abdominal cramping, bloating, and a change in bowel habits. Some people with the disorder have constipation. Some have diarrhea. Others go back and forth between the two. Although IBS can cause a great deal of discomfort, it does not harm the intestines.

IBS is common. It affects about twice as many women as men and is most often found in people younger than 45 years. No one knows the exact cause of IBS. There is no specific test for it. Your doctor may run tests to be sure you don't have other diseases. These tests may include stool sampling tests, blood tests, and x-rays. Your doctor may also do a test called a sigmoidoscopy or colonoscopy. Most people diagnosed with IBS can control their symptoms with diet, stress management, probiotics, and medicine.

Celiac disease is an immune disease in which people can't eat gluten because it will damage their small intestine. If you have celiac disease and eat foods with gluten, your immune system responds by damaging the small intestine. Gluten is a protein found in wheat, rye, and barley. It may also be in other products like vitamins and supplements, hair and skin products, toothpastes, and lip balm.

Celiac disease affects each person differently. Symptoms may occur in the digestive system, or in other parts of the body. One person might have diarrhea and abdominal pain, while another person may be irritable or depressed. Irritability is one of the most common symptoms in children. Some people have no symptoms.

Celiac disease is genetic. Blood tests can help your doctor diagnose the disease. Your doctor may also need to examine a small piece of tissue from your small intestine. Treatment is a diet free of gluten.

An intestinal obstruction occurs when food or stool cannot move through the intestines. The obstruction can be complete or partial. There are many causes. The most common are adhesions, hernias, cancers, and certain medicines.

Symptoms include

• Severe abdominal pain or cramping
• Vomiting
• Bloating
• Loud bowel sounds
• Swelling of the abdomen
• Inability to pass gas
• Constipation

A complete intestinal obstruction is a medical emergency. It often requires surgery.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases