In the later stages of the disease the colon is often narrowed and shortened, with decreased absorption of water, rectal urgency and poor control of bowel function. Abdominal pain is another common symptom. Since the intestine has a muscular coat, it is subject to muscle spasm, just as muscles anywhere in the body. The intestine is also richly supplied with nerve elements. Often, the pain due to intestinal spasm is cramping in nature.
Pressure can build up behind the narrowed intestine and produce cramps.
Occasionally, the narrowing is so severe that a blockage of the intestine occurs, requiring immediate medical, and less frequently surgical, attention. A sudden, short, severe type of pain at the opening of the rectum is called tenesmus and results from inflammation and spasm in the rectum. Fever is a frequent accompaniment of inflammation of any type and is common in Crohn's. Weight loss is common due to the bowel's inability to absorb sufficient nutrition. In children, a failure or delay in growth and maturity may result.