Crohn's disease (symptoms and types)

Authors : Adam S. Cheifetz MD Center for Inflammatory Bowel Disease, Alan C. Moss MD Beth Israel Deaconess Medical Center, Mark A. Peppercorn MD Harvard Medical School Boston, MA

What are the symptoms of Crohn’s disease?
The symptoms of Crohn’s disease can vary from mild to severe. Abdominal pain and diarrhea are the most common symptoms of Crohn’s disease. However, GI bleeding, nausea, weight loss, fever, and fatigue can also be seen. Crohn’s disease can also affect other parts of the body, including the joints, skin, liver, and eye. These are called extraintestinal manifestations (see below) and are rarely the first symptom with which a Crohn’s disease patient presents. Children can present with delayed development and growth. Approximately 1/3 of Crohn’s patients will develop symptoms around the anus (perianal), including skin tags, fissures (tears in the anal skin), fistulae (abnormal connection between the intestine and the anus), or abscesses.
Common symptoms of Crohn's disease

• Diarrhea
• Abdominal pain and tenderness
• Loss of appetite and weight
• Fever
• Fatigue
• Rectal bleeding
• Perianal lesions
• Stunted growth in children
• Complications : fistula, perforation, abcess
• UGI symptoms
• Extra-intestinal manifestations

The symptoms described above, however, are not specific for Crohn’s disease and can be seen in many other conditions. The following is a partial list of other conditions that may mimic Crohn’s disease, also known as a list of differential diagnoses.
• Infectious causes – bacterial, viral, or parasitic infection.
• Ischemia – low blood flow to the small intestine or colon, usually seen in older patients
• Medication – non-steroidal anti-inflammatories, antibiotics, birth control pills
• Diverticulitis – infection of a diverticulum (outpouching of colon) that can present with left lower quadrant pain and fever
• Appendicitis – usually presents with right lower quadrant abdominal pain and fever
• Irritable bowel syndrome – can cause severe diarrhea and abdominal pain
• Lactose intolerance – can cause diarrhea, bloating, and abdominal pain. Patients with Crohn’s disease can also have lactose intolerance.
• Celiac disease – sensitivity to gluten (wheat) which can cause diarrhea and bloating.
• Gallstones
• Cancer, lymphoma
• Diseases that affect other organs in the abdomen also need to be considered such as: Endometriosis, pelvic inflammatory disease, ectopic pregnancy, ruptured ovarian cyst, kidney stones, bladder or kidney infections.

Therefore, symptoms alone are not enough to diagnose someone with Crohn’s disease. Patients require further workup or testing. It is also important to remember that even in patients with well established Crohn’s disease, not all abdominal symptoms are related to their disease. Patients with Crohn’s disease are just as susceptible to the development of GI infections, kidney stones, gallstones, etc., as are patients without Crohn’s disease. It is important for patients and physicians to keep this in mind at all times. Because Crohn’s disease can affect any part of the GI tract and any layer of the intestinal wall (transmural), the symptoms are quite variable and often depend on the location and type of Crohn’s disease. Although the location of Crohn’s disease varies from patient to patient, it often remains constant within a given patient. In other words, it would be extremely rare for a patient with pure ileitis to suddenly develop Crohn’s disease involvement in their colon as well. While the location of disease tends to remain constant, the type and severity of Crohn’s disease can change over time as a result of persistent inflammation. For example, many patients with inflammatory disease will eventually go on to develop either fibrostenosing or perforating disease.

Types of Crohn’s disease (location)
1. Gastroduodenal Crohn’s disease – also known as upper GI Crohn’s disease: Uncommon – symptoms in approximately 5% of patients. Affects the stomach and first part of the small intestine (duodenum) Symptoms include nausea, loss of appetite, weight loss, vomiting, and pain in the upper abdomen
2. Jejunoileitis – inflammation of the second part of the small intestine (jejunum): Uncommon Symptoms include diarrhea, abdominal pain (usually after eating), malnutrition due to malabsorption of nutrients, and weight loss
3. Ileitis – inflammation of the last part of the small intestine (ileum) Occurs in approximately 30% of patients Symptoms include diarrhea, abdominal pain (often in the right lower quadrant), and weight loss
4. Ileocolitis – inflammation of the ileum and colon (most often the right side of the colon): Most common type of disease, affecting approximately 50% of patients Symptoms similar to Crohn’s ileitis: diarrhea, abdominal pain (often in the right lower quadrant), and weight loss
5. Crohn’s colitis – inflammation of the colon only: Not uncommon. Approximately 20% of patients with Crohn’s Symptoms include diarrhea, rectal bleeding, and abdominal pain Perianal disease and the extraintestinal manifestations of Crohn’s disease are more common in patients with involvement of the colon. Unlike in ulcerative colitis, where the inflammation is continuous and almost always starts in the rectum, working its way back into the colon, Crohn’s disease often spares the rectum. In addition, Crohn’s disease is often not continuous; there can be a healthy segment of bowel between diseased segments. This type of involvement is typical of Crohn’s disease and is referred to as a “skip lesion.”
6. Perianal disease Affects up to 1/3 of patients with Crohn’s disease. Patients can present with fistulae, fissures, skin tags, or abscesses  :

• Perianal fistulas: perianal fistulas result from small collections of inflammation and infection that tunnel their way from the anal muscle (sphincter) to the skin around the anus. This leads to drainage of mucus, stool, or pus from openings around the perianal area. If the external opening closes, an abscess may develop, which characteristically will present with swelling and pain in the perianal area, and associated fever. Typically, this requires treatment with antibiotics and, often, surgical drainage. 
• Fissures: fissures are sores or ulcerations in the lining of the skin that crosses the anal canal; often, these can be quite painful. 
• Skin tags: patients with Crohn’s can develop fleshy growths just outside the anus which are known as skin tags. Occasionally, these can be confused with hemorrhoids. They are usually not painful or clinically relevant. 

Distribution of Crohn's Disease in the intestinal tract 

Types of Crohn’s disease (disease pattern).
The symptoms and signs of Crohn’s disease are a function of not only the location of disease, but of the pattern of disease.
1. Inflammatory: A form of Crohn’s disease that is due to inflammation of the intestine. Symptoms include diarrhea, abdominal pain, weight loss, fever, bleeding, fatigue, loss of appetite, and growth retardation (children). Patients can also develop small bowel obstructions (see below) or a mass in their right lower quadrant. These patients respond best to medical therapy. This pattern is typical early in the course of Crohn’s disease.
2. Fibrostenotic: A form of Crohn’s disease that is usually seen in patients with Ileal disease. Over time, persistent inflammation can lead to scarring within the intestinal wall. Continued build-up of scar tissue within the intestinal wall causes narrowing of the intestine itself. Eventually the gut becomes so narrow that even a small amount of inflammation causes closure of the lumen, resulting in a small bowel obstruction. These small bowel obstructions are characterized by severe abdominal pain, nausea, vomiting, and lack of passing bowel movements (constipation) or gas from below. Patients with known stricturing disease will likely be asked to follow a low-residue diet. Most small bowel obstructions resolve quickly with conservative therapy (nothing to eat, intravenous fluids). Eventually, patients with fibrostenotic disease are likely to require surgery to remove the scarred section of bowel to prevent recurrent small bowel obstructions in the future

Barium study showing (arrows) narrowing in the small bowel from Crohn's disease

3. Perforating/Fistulizing: Because Crohn’s disease can affect all layers of the bowel wall (transmural), patients can develop a perforation of the intestine, leading to leakage of bowel contents into the abdominal cavity, or they can develop a fistula, which is an abnormal connection or tunnel from one loop of bowel to another or even to another organ.
a) Perforation – can present acutely with severe abdominal pain, rigid abdomen (“surgical abdomen”), fever, and chills. The symptoms can be similar to those of appendicitis. Alternatively, it can present more indolently with a mass in the abdomen, fever, chills, and less severe pain. A perforation usually results in an intraabdominal abscess (collection of bacteria and inflammatory cells) that requires antibiotics and drainage, either surgically or via a radiologically-placed drain.
b) Fistula - The symptoms of a fistula depend on the organ to which the fistula connects: Examples of different types of fistula include bladder (entero-vesical), vagina (entero-vaginal), skin (entero-cutaneous), and intestine (entero-enteric). The most common type of fistula is actually a perianal fistula, but this entity will be considered separately below. · Entero-vesical fistulae often lead to recurrent urinary tract infections. Patients may also complain of passing gas, blood, or stool when they urinate. · Entero-vaginal fistulae may present with passage of gas or stool through the vagina. · Entero-cutaneous fistulae cause drainage of the bowel contents through the skin’s surface. · Entero-enteric fistulae can be asymptomatic or may present with diarrhea or an abdominal mass.