Up to a million Americans are thought to have some form of inflammatory bowel disease, according to the Crohn's and Colitis Foundation of America (CCFA); about half of them have ulcerative colitis and the other half have Crohn's disease. Crohn's, which most commonly develops in adolescents and young adults, is a chronic disease affecting the gastrointestinal system---also called the GI tract.
Diarrhea
The key feature of Crohn's is inflammation that occurs in the GI tract. This chronic inflammation causes swelling of the lining of the intestines, and eventually leads to scarring. The scar tissue prevents water and salts from being absorbed by the body, according to the Mayo Clinic, which gives rise to the persistent diarrhea that is a hallmark of Crohn's.
Abdominal Pain
The degree of abdominal cramping and pain associated with Crohn's depends on the degree of severity of the disease. For some, it is fairly limited, for others, it can be quite severe, according to the CCFA. This cramping happens because the swelling and scarring resulting from the inflammation in the GI tract constricts the muscles that usually move the digestive products through the system. In Crohn's, the pain and cramping is often found in the right lower area of the abdomen, where the ileum is located. According the online Merck Manual for Healthcare Professionals: "About 35% of Crohn's disease cases involve the ileum alone (ileitis); about 45% involve the ileum and colon (ileocolitis), with a predilection for the right side of the colon."
Rectal Bleeding
The inflammation and swelling of Crohn's can damage the intestinal lining in a number of ways. Ulcers or fistulas can develop, with concomitant bleeding that the Mayo Clinic describes as bright red blood in the toilet or darker red blood mixed with stool. If the bleeding is persistent, anemia may result. The thickening and scarring can narrow the intestine and may cause fissures in the anus or even blockage of the intestinal tract, requiring surgical intervention to remove the damaged section of bowel.
Poor Appetite and Weight Loss
The combination of abdominal cramping and diarrhea frequently induces a loss of appetite; the inability to properly digest food compounds the problem, leading to weight loss. The resultant nutritional complications, according to the National Institute of Diabetes and Digestive and Kidney Diseases, may include deficiencies of proteins and vitamins, as well as inadequate caloric intake.
Other Possible Signs
Fatigue is another common complaint among Crohn's sufferers, along with fevers associated with the chronic inflammation. According to the CFFA, Crohn's can also affect the joints, eyes, skin and liver. Growth and sexual development also may be delayed in children who have Crohn's disease.
