Ogilvie syndrome is a rare condition that affects the large intestines (colon). Although the signs and symptoms mimic those of an intestinal blockage, there is no physical obstruction. Instead, the symptoms are due to nerve or muscle problems that affect peristalsis (the involuntary, rhythmic muscular contractions that move food, fluid, and air through the intestines). In people affected by Ogilvie syndrome, the symptoms come on suddenly and may include abdominal pain, nausea, vomiting, abdominal distention (swelling), constipation, and/or diarrhea. If untreated, the condition can cause malnutrition, bacterial overgrowth in the intestines, and weight loss. The underlying cause of Ogilvie syndrome is poorly understood. However, it usually occurs in adults when the colon becomes enlarged after surgery, illness or injury. Treatment options for Ogilvie syndrome include supportive therapy that addresses associated symptoms, medications, decompression (a procedure that reduces pressure within the colon) and surgery.