Crohn’s disease is a chronic inflammatory bowel disease that primarily can affect any part of the gastrointestinal tract from the mouth to the anus. While it tends to cause gastrointestinal symptoms such as bloating, flatulence, cramping, diarrhea, nausea, vomiting, and blood in stools, the disease can cause additional symptoms when it affects other systems in the body. Complications include bowel obstruction and intestinal rupture, and there may also be an increased risk of bowel cancer in those with Crohn’s. When its effects go beyond the gastrointestinal tract, the disease can lead to severe complications ranging from vision impairment and arthritis to skin ulcers, osteoporosis, liver failure, and more.
The gastrointestinal (GI) tract is the organ system primarily affected by Crohn’s disease. Approximately 30 percent of cases involve the small intestine, particularly the terminal ileum (the junction through which partially digested food moves from the small to the large intestine).1 Another 20 percent involve only the colon, while 45 percent involve both the small intestine and the colon.
Among the characteristic symptoms of Crohn’s disease:1
- Abdominal pain is usually the first sign and is often concentrated to the lower right side of the abdomen, where the terminal ileum is located. The pain may be accompanied by cramping, bloating, flatulence, and nausea.
- Diarrhea is also common and can vary based on the location of the inflammation. Inflammation of the ileum (ileitis) usually results in watery stools. By contrast, inflammation of the colon (colitis) usually results in more frequent bouts of varying consistencies.
- While blood in stools is less common with Crohn’s disease than with ulcerative colitis (a related disorder also classified as an inflammatory bowel disease), it can sometimes be profuse if the intestinal inflammation is severe.
- Nausea and stomach pain will typically lead to poor appetite and an associated loss of weight. The poor absorption of food and nutrients may further accelerate weight loss.
Inflammation in the GI tract is not limited to the intestines alone. Recurrent mouth sores (aphthous ulcers) are common in people with Crohn’s disease, while anal itchiness, fistulas, fissures, or abscesses can lead to extreme discomfort and fecal incontinence. The stomach and esophagus are less commonly affected.
Under the persistent burden of inflammation, the walls of the intestines will undergo a consistent, overall thickening as layers of scar tissue begin to build up. This not only causes the narrowing of the intestinal passage, but it also increases overall inflammation and your risk of short- and long-term complications.
- Bowel obstruction is the most common complication of Crohn’s disease and may be mild or severe, depending on the degree of obstruction. Symptoms include cramping, bloating, and vomiting.
- Intestinal abscesses (localized pockets of pus caused by bacteria) can cause abdominal pain, tenderness, and fever.
- Intestinal fistulas are abnormal openings through which gastric fluids can leak and cause skin and other organs.
- Bowel perforation (rupture) may occur due to an abscess or fistula, allowing the contents of the intestines to spill into the abdominal cavity and cause severe infection (peritonitis).
- Toxic megacolon is a rare but severe complication of Crohn’s disease in which the colon suddenly dilates and loses its ability to contract. Symptoms include painful bloating pain, fever, rapid heart rate, and intestinal bleeding. If left untreated, the buildup of gas can lead to rupture, septic shock, and death.
Perhaps the most serious concern is the increased risk of colorectal cancer.2 The persistent intestinal inflammation can sometimes trigger genetic changes in cells that cause them to divide abnormally and develop cancer. In people with Crohn’s disease, the area most commonly affected is the small bowel, but it can affect any part of the small or large bowel.
Inflammation of the middle layer of the eye (uveitis) can cause blurred vision, light sensitivity, and eye pain.1 When it affects the white of the eye (sclera), it can lead to episcleritis. Both are usually benign conditions that resolve independently but, under the burden of chronic inflammation, can lead to permanent damage and vision loss.
Joints and Connective Tissue
Crohn’s disease is associated with a group of conditions called seronegative spondyloarthropathy. One or more joints are affected by arthritis, or more muscle attachments are affected by enthesis’s. In people with Crohn’s disease, there are three areas typically affected by arthritis:1
- Larger, weight-bearing joints of the knees, hips, shoulders, elbow, and wrist
- Five or smaller joints on the hands or feet, occurring symmetrically (meaning either in both hands or both feet)
- The spine, leading to ankylosing spondylitis
The symptoms of arthritis include painful, warm, swollen, and stiff joints accompanied by the loss of joint mobility.
The most common skin condition associated with Crohn’s disease is erythema nodosum, which appears as raised, tender, red nodules, mainly around the shins. The nodules are caused by inflammation of adipose (fat) cells in the deeper subcutaneous layer of skin.
Another, more severe skin condition is called pyoderma gangrenosum. This painful condition is characterized by an ulcerative sore that usually begins on the leg as a tiny bump but can increase in size, causing significant tissue death (necrosis).
Osteoporosis, a condition characterized by the loss of bone mass, is common in adults with long-term Crohn’s disease.3 It can not only cause lower back pain, but it can significantly increase the risk of a fracture. Clubbing of the fingers is also occasionally seen.
Children with Crohn’s disease are also prone to delayed development, generally related to delayed skeletal development. Over 50 percent of these children will be of subnormal height, while around 25 percent will have short stature (defined as two deviations below the mean height for the child’s age and gender). Puberty is also frequently delayed.
Crohn’s disease decreases the intestines’ ability to reabsorb bile that the gallbladder and liver have secreted for digestion. The imbalance in secretion and reabsorption can lead to the accumulation of bile salts in the gallbladder, resulting in an increased risk of gallstones.
Gallstones can be incredibly painful and cause cramping, indigestion, nausea, vomiting, and pain in the back or upper-right abdomen.
Central Nervous System
It is estimated that one of every seven people with Crohn’s disease experiences neurological symptoms. They may be mild to moderate and include a headache, depression, or a tingling or numb sensation in the hands and feet (neuropathy). Others may be more serious and include:4
- Anterior ischemic optic neuropathy, the sudden loss of central vision due to the decreased blood flow to the optic nerve
- Posterior reversible encephalopathy syndrome (PRES), a nerve disorder characterized by a headache, confusion, seizures, and visual loss
- Chronic axonal polyneuropathy, which can manifest with loss of motor control and sensation
The neurological symptoms of Crohn’s disease are poorly understood. Severe complications are believed to be linked to severe, long-term untreated illness.
The symptoms of Crohn’s disease can be so diverse and variable that it may be challenging to know when to see a practitioner. Ultimately, the one factor that separates Crohn’s disease from your run-of-the-mill gastrointestinal problem is the persistence of symptoms.
See a Healthcare Provider If You Have:
- Ongoing bouts of diarrhea that don’t respond to over-the-counter (OTC) remedies
- Abdominal pain that is either persistent or recurring
- Blood in the stool
- Unexplained weight loss
- Unexplained fever lasting for more than a couple of days
- A family history of inflammatory bowel disease (IBD), including Crohn’s disease or ulcerative colitis
The good news is that, if treated appropriately, the outlook for people living with Crohn’s disease is very positive. Despite its impact on your health, it is not a condition associated with a shortened lifespan. With early diagnosis and treatment, you can avoid many of the long-term complications of the disease.