Crohn's Disease - Signs And Symptoms
Crohn's disease is a chronic condition of the digestive tract, characterized by chronic inflammation extending through all layers of the intestinal wall, and also involving the regional lymph nodes. The original description of this disease by Crohn, Ginzberg and Oppenheimer in 1932 localized it to segments of the ileum (latter part of small intestines). However, the same process may involve the inner lining of the mouth, esophagus or food pipe, stomach, and duodenum, as well as jejunum and ileum (parts of small intestines). Crohn's disease of small intestines is also known as regional enteritis. When the disease involves the large intestines, either alone, or with accompanying small intestine involvement, then it may be referred to, as Crohn's disease of the colon. This disease is increasing steadily in terms of incidence and prevalence. The condition usually peaks between the ages of 15 and 35, but can occur in every decade of life.
Signs and Symptoms of Crohn's disease include pain abdomen, diarrhea, fever and weight loss
Causes Of Crohn's Disease
Our digestive tract begins from the mouth, includes parts of the pharynx, esophagus or food pipe, stomach, small intestines (comprising of the duodenum, jejunum, and ileum), large intestines (comprising of ascending, transverse, descending and sigmoid colon), rectum and anus. Crohn's disease is caused by a focal decrease in blood supply in certain regions of the small intestines, that occurs due to vasculitis (an inflammation of the blood vessels supplying the intestines). This vasculitis arises due to an imbalance in the body immunity, that attacks the harmful microbes to destroy them, and in that process ends up hurting the digestive tract. The predisposing factors for Crohn's disease include the following:
- Genetics: Many of the suffering individuals have a first-degree relative with the disease.
- Infections: The disease has some features suggesting chronic infection, but no microbe has been pinpointed as a single causative agent. Similarities between Crohn's disease and tuberculosis of the intestines have focused attention on mycobacteria, the agents responsible for causing tuberculosis.
- Food: It is believed that with the advent of refrigeration the intake of frozen and stale foods increased. These frozen food items, especially non-vegetarian food could harbor harmful bacteria that initiate an infection of the digestive tract. In the course of time, repeated attacks of gastroenteritis could increase the chances of acquiring this disease.
- Smoking: It causes a three-fold increase in the disease risk.
- Immunological factors: Individuals suffering from this condition have antibodies to the bacteria E.coli, to cow's milk protein, and also have increased titers of immune complexes that cause damage to other organs in the body. Yogurt and other probiotics seem to have a protective effect against the disease. Cell-mediated immunity necessary to fight harmful microbes is also diminished and is characterized by cutaneous anergy or diminished responsiveness of skin immune cells to various stimuli, and a reduction in the number of T-lymphocytes.
- Psychological factors: Most people suffering from this condition have a characteristic personality that renders them susceptible to emotional stress. The disease episode is frequently precipitated or exacerbated by a stressful event.
Crohn's Disease usually begins after an episode of gastroenteritis
Changes In The Intestines Caused By Crohn's Disease
Crohn's disease most commonly affects the small intestines, that also ileum (the latter half). The remainder may involve large intestines and other parts of the digestive tract. Lesions around the anus are common. Mouth, food pipe or esophagus, stomach and duodenum are rarely affected. It leads to fibrosis and strictures in the affected regions. Parts of the intestine above the stricture are dilated. In the affected area, deep ulcers form on the inner lining of intestines in linear or snake-like patterns. Fluid collects in the inner lining of intestines in between the ulcers, making it appear swollen or edematous. This gives rise to a "cobblestone appearance" of the inner surface of intestines. Severe inflammation leads to adhesions, abscesses, and fistulae or tracts opening into adjacent organs. The surrounding lymph nodes are enlarged. Adjacent loops of small intestine may become adherent or matted together, leading to a mass that can be felt in the right lower part of the abdomen.
The disease is discontinuous, occurs in patches, with islands of inflamed areas interspersed within the normal intestinal lining. These are called skip lesions. The earliest signs are the formation of tiny aphthous ulcers in small intestines, along with areas of occlusion or blockage of arteries supplying the affected area.
The disease could involve small intestines only, large intestines only, or be an ileocolic involvement (affecting parts of both). In a small number of individuals, mostly children and adolescents, there is a diffuse and extensive ulceration of the jejunum and ileum (parts of the small intestine). Many a time, it becomes impossible to distinguish this condition from Ulcerative colitis, another inflammatory bowel disorder.
Symptoms Of Crohn's Disease
What are the common symptoms of Crohn's disease?
Complications Of Crohn's Disease
- Abscess formation.
- Intestinal obstruction
- Internal bleeding
- Intestinal cancer
Signs And Symptoms Of Crohn's Disease
The major clinical features of this disease are fever, pain abdomen, diarrhea (often without blood) and generalized friability, along with associated weight loss. When large intestines are involved, diarrhea and pain are the most frequent symptoms. Bleeding per rectum is less common, but fistulas, fissures, and perirectal abscesses do occur.
The condition presents as an unexplained tiredness, weight loss, pain in the right lower abdomen, and diarrhea. Low-grade fever, loss of appetite, nausea and vomiting also accompany this condition. Pain abdomen may be constant at times, or present as a colic or as cramps. The diarrhea is moderate and without gross bleeding. After months of repeated attacks, the affected area of the intestines begins to narrow to form strictures with fibrosis. This causes severe abdominal pain on eating, and the affected individual develops what is known as "food fear". This disease may lead to intestinal obstruction, perianal sepsis (infection and septic formation around the anus and spread of infection to the entire body via the bloodstream), or a urinary tract infection resulting from a fistula from intestines into the urinary bladder. Extensive involvement of the small intestines can result in malabsorption.
Right lower quadrant of the abdomen is tender to touch, and associated fullness or mass may be felt, that reflects the adherent loops of intestines.
Local Complications Of Crohn's Disease
- Intestinal obstruction: This is a frequent complication. In the initial stages of disease, acute inflammation and swelling of the involved intestinal segment, usually the terminal part of the small intestine that opens into the large intestines, causes the blockage. However, as the disease progresses, fibrosis occurs, strictures form and obstruction occurs due to narrowing of the lumen of intestines.
- Fistula formation: A fistula is a tunnel that bores through the walls of two adjacent organs, and connects them with each other. This is a frequent complication when this disease involves small intestines. Fistulas occur between adjacent segments of small intestines. They may also burrow into other areas, and even create an opening into the skin (cutaneous fistulas), or develop collections of pus called abscesses. In a large number of instances, the first indication of the disease may be the presence of rectal fissures, abscess or fistula.
- Perforation: This is a rare complication.
- Ulcers in the mouth: Multiple aphthous ulcers may occur in the mouth, stomach and duodenum, the symptoms of which may, at times mimic those of peptic ulcer disease. Later in the course of the disease, chronic scarring may produce gastric outlet or duodenal abnormalities.
- Cancer: Longstanding Crohn's disease can lead to the small intestine and colon cancers though the chances of malignancy are low.
- Gall bladder stones: An extensive form of disease involving the small intestines may cause bile acid malabsorption. This leads to a decrease in the bile salt pool, and an increased tendency of stone formation in the gall bladder.
- Increased risk of kidney stones: When Crohn's disease involves only the small intestines, and the colon is intact, there is an increased absorption of oxalates from the diet through the colon or the large intestines. This results in their increased levels in the urine, and development of urinary oxalate stones. Dehydration due to recurrent attacks of diarrhea also increases the risk of kidney stones.
Crohn's Disease - the overall picture
- It is a chronic inflammatory disease involving the small and large intestines.
- More common between 15-30 years age.
- Presents as intermittent bouts of diarrhea, pain abdomen, fever and weight loss.
- Increases risk of gallstones and kidney stones.
In my subsequent hubs, I would discuss Ulcerative Colitis, and complications and extraintestinal manifestations of Inflammatory Bowel Disease.
Forbes A. Kalantzis (2005): Crohn's disease: The cold chain hypothesis". International Journal of Colorectal disease 21 (5): 399-401. doi : 10.1007/s00384-005-0003-7 PMD 16059694