Crohn's disease - symptoms, types, causes, prognosis, diagnosis

Crohn's disease (regional enteritis, granulomatous ileitis or colitis) is a granulomatous inflammation of the digestive tract of unknown etiology with a predominant localization in the terminal ileum.

You can read about the treatment of Crohn's disease in the article “ How to treat Crohn's disease? »

Types of Crohn's disease

The disease was described by BB Crohn and GD Oppenheimer in 1932. Nonspecific inflammation occurs in the submucosa and subsequently spreads to the mucous membrane and the entire intestinal wall. The inflammatory process is segmental in nature - the affected segments alternate with unaffected ones.

Depending on the location of the pathological process, two types of Crohn's disease are distinguished:

Type 1:

• the lesion is limited to one segment of the small intestine;
• the ileocecal region is affected;
• the lesion is limited to a segment of the colon.

Type 2:

• segments of both the small and large intestines are affected;
• there is a combination of intestinal damage to the stomach, esophagus or oral mucosa,
• granulomatous inflammation of the appendix (appendix) is also possible.

Causes

The cause of the disease is unknown. At different times, several hypotheses were put forward, including immunological and infectious. The role of viruses, chlamydia and bacteria, especially mycobacteria, has been suggested.

Observations show that dietary supplements and lack of fiber in foods play a role in the increased incidence of Crohn's disease.

However, none of these hypotheses have been proven. A family predisposition to the disease is observed in approximately 20% of patients, which suggests the influence of genetic factors.

Development of the disease

The earliest microscopic sign of damage in Crohn's disease is a tiny ulceration of the mucous membrane (aphtha). The inflammatory process gradually spreads to all layers of the intestinal wall and is especially pronounced in the submucosa, where infiltrates (granulomas) are formed.

Granulomas consist of clusters of lymphocytes, in the center of which single giant cells of the Pirogov-Langhans type can be found. Unlike tuberculous granulomas, Crohn's disease never develops foci of caseous necrosis.

Infiltration extends to both the mucous and serous membranes of the intestinal wall. As a result, the intestinal wall becomes dense, the mucous membrane acquires relief, and multiple erosions and ulcers like cracks are formed on its surface, penetrating the entire intestinal wall. Sometimes ulcers perforate, which leads to the formation of intestinal fistulas. Scar changes in the wall can lead to a narrowing of the intestinal lumen, the development of partial and even complete intestinal obstruction.

The relief of the mucous membrane often takes on a peculiar cobblestone appearance due to infiltration of the intestinal wall with lymphoid cells and its intersection with deep cracks and linear ulcers.

The main feature of the histological picture of Crohn's disease is a typical transmural lesion of the intestinal wall. Inflammation can spread to the serosa and adjacent tissues and organs, forming fistulas and adhesions.

Another characteristic feature of the disease is the formation of non-caseating sarcoid-like epithelioid granulomas with Pirogov-Langhans cells.

Granulomas are found in approximately 30-40% of cases during histological examination of biopsy material. When examining surgical material, granulomas are found much more often, including in the mesenteric lymph nodes.

The presence of granulomas is characteristic of Crohn's disease, but their absence does not provide grounds for its exclusion. Histological examination allows us to see pronounced infiltration of the lamina propria of the mucous membrane and submucosa with lymphoid cells, thick-walled vessels with symptoms of vasculitis.

The process may involve the mesentery, which becomes swollen and thickened. The mesenteric lymph nodes are enlarged and contain large numbers of inflammatory cells, indicating chronic inflammation. Transmural inflammation, deep ulcers, edema and fibrotic changes in the intestinal wall create conditions for obstruction, fistulas and abscesses.

The affected segments of the small intestine are sharply demarcated from adjacent normal intestinal loops, corresponding to the concept of “regional enteritis.”

The pathological process in Crohn's disease is most often located in the terminal part of the small intestine (ileocecal region), although it can be located in any part of the digestive tract - from the oral cavity to the anus.

Isolated damage to the ileum is observed in approximately 35% of cases, the ileum and colon - in 45%; Crohn's disease of the colon occurs in approximately 20%.

Isolated damage to the anorectal area is observed in only 3% of patients.

Symptoms

The manifestations of Crohn's disease depend on the part of the intestine in which the inflammatory process develops and its severity.

General symptoms that are characteristic of all types of Crohn's disease:

• diarrhea;
• stomach ache;
• fever;
• weight loss;
• anal fissure.

Diarrhea

Diarrhea is common in all patients, but it varies.

At the height of the disease, persistent diarrhea is most typical (stools 2-3 times a day, copious, semi-formed, less often liquid, watery).

When the ileum is damaged, the absorption of bile salts is impaired, which causes increased secretion of ions and water in the colon and leads to hologenic diarrhea.
If more than 100 cm of the ileum is affected, steatorrhea develops. Some patients may experience miasmas (false urge to defecate), but unlike ulcerative colitis, there may be no blood in the stool.

Abdominal pain with CD

• Most often the right lower abdomen hurts, pain occurs immediately after eating.
• In case of obstruction, the pain is strong and cramping.
• The formation of an abscess (abscess) is indicated by constant pain with fever and an increase in white blood cells.

Low-grade fever and general malaise in Crohn's disease

These manifestations are characteristic of inflammatory bowel disease. A high temperature indicates an exacerbation of the process, the formation of an abscess.

Weight loss

This symptom can be very pronounced, up to extreme exhaustion of the body, general weakness, sudden weight loss, and a decrease in the activity of physiological processes.

Anal fissure

Examination of the anus and rectum often reveals

• anal fissure;
• proctitis;
• paraproctitis.

Sometimes anal fissure and paraproctitis can precede Crohn's disease or be its main manifestation. In this case, conservative treatment of these manifestations does not bring any positive results. Therefore, every case of persistent fistula or anal fissure of the rectum should be checked for the presence of Crohn's disease in the patient, including in another part of the intestine.

Forms of the disease

Crohn's disease, which affects the intestines, has the following forms:

• acute ileitis (ileotiphlitis);
• jejunoileitis with small bowel obstruction syndrome;
• chronic jejunoileitis with malabsorption syndrome;
• granulomatous colitis;
• granulomatous proctitis.

Acute form of the disease

When acute inflammation occurs, the symptoms are similar to an exacerbation of appendicitis.
Sharp pain in the right lower abdomen, fever. During laparotomy, inflammation of the ileum is detected.

If there is perforation or necrosis of the intestine, part of it is removed. In other cases, the entire intestine is inspected and the mesentery of the small intestine is infiltrated with a solution of novocaine with an antibiotic.

Stenosing form (jejunoileitis with small bowel obstruction syndrome)

Crohn's disease can last a long time with vague abdominal pain and extraintestinal symptoms (episodes of causeless fever, joint pain, erythema nodosum, etc.). The disease may remain unidentified for many years. If it begins in childhood, the child lags behind in physical and sexual development.

Over time, as intestinal obstruction , attacks of pain appear, more often in the right iliac region (lower right abdomen), vomiting, bloating, loud rumbling and sounds of fluid transfusion, stool and gas retention.

Visible peristalsis appears on the abdominal wall in the form of periodically rising “shafts”.

Crohn's disease with a primarily chronic course

Chronic jejunoileitis with malabsorption syndrome is manifested by symptoms of intestinal malabsorption:

• frequently recurring diarrhea;
• anemia (low hemoglobin in the blood);
• decreased protein in the blood (hypoproteinemia);
• swelling;
• fever.

The severity of pain and severity of fever depend on the degree of inflammation and intestinal obstruction.

Granulomatous colitis

This type of disease exhibits symptoms such as:

• stomach ache;
• fever;
• unshaped chair;
• mucus in stool;
• blood in stool.

Granulomatous proctitis

The main manifestations are:

• long-term non-healing anal fissures;
• anal fistulas.

If inflammation affects only the colon, then the symptoms of granulomatous colitis and proctitis may be no different from ulcerative colitis.

Crohn's disease of the appendix

Usually this disease manifests itself as an attack of acute appendicitis. The symptoms differ from appendicitis in that they are less acute and sometimes form a dense infiltrate in the lower right abdomen.

Extraintestinal manifestations of Crohn's disease

Quite often this disease manifests itself with symptoms that seem to have nothing to do with intestinal inflammation. Conventionally, all manifestations can be divided into three groups.

First group: combination of extraintestinal symptoms with intestinal ones

In approximately 1/3 of patients, the intestinal symptoms described above are combined with

• joint damage (arthritis),
• inflammatory eye disease (episcleritis),
• stomatitis (inflammation of the oral mucosa),
• inflammation of the skin and subcutaneous vessels (erythema nodosum),
• skin lesions (pyoderma gangrenosum).

These same symptoms may accompany ulcerative colitis.

These diseases are related to the condition of the intestines and do not require separate treatment.
Sometimes extraintestinal manifestations are the first signs of Crohn's disease and ulcerative colitis.

Second group: extraintestinal manifestations requiring special treatment

This group includes the development of Crohn's disease when, in addition to the intestines, other organs and systems are affected. For example,

• spinal lesions (ankolosing spondylitis and sacroiliitis),
• inflammation of various parts of the uvea (uveitis),
• inflammation of the bile ducts (cholangitis).

In this case, special treatment of the affected organs and systems is necessary.

Third group: malabsorption

As described above, damage to the small intestine in Crohn's disease causes disruption of absorption processes. This leads to the development of diseases such as:

• urolithiasis disease;
• cholelithiasis;
• anemia;
• blood clotting disorders.

In addition, hydronephrosis may develop as a result of compression of the urethra and urinary tract by infiltrates in the pelvis and retroperitoneum.

Extraintestinal manifestations of CD

Related to process activity	Arthritis, osteoporosis, conjunctivitis, episcleritis, iritis, aphthous ulcers, erythema nodosum, pyoderma gangrenosum
Not related to process activity	Arthralgia, sacroiliitis, ankylosing spondylitis, osteomalacia, maldigestion, cholelithiasis, fatty liver, primary sclerosing cholangitis, urolithiasis, ureteral strictures, right-sided hydronephrosis, amyloidosis

Complications of CD

Complications of Crohn's disease include:

• obstruction of the small intestine,
• abscesses in the abdominal cavity, pelvic cavity and ischiorectal region,
• fistulas,
• short bowel syndrome,
• perforation,
• massive bleeding from the rectum,
• colorectal cancer.

Can Crohn's disease be cured?

In an acute attack of Crohn's disease, recovery occurs in 95% of patients; in the rest, the disease takes a chronic form.

It is impossible to completely recover from the chronic form of Crohn's disease. Even removing part of the intestine does not guarantee a complete cure.

It is believed that the risk of cancer in patients with CD is quite high. Both domestic and foreign doctors do not have a definite opinion on this matter.

Some researchers provide evidence of a high incidence of cancer in patients with Crohn's disease.

However, most doctors argue that if such statistics exist, then the percentage of such cases is very low compared to the general statics of cancer development among the population, and life expectancy with Crohn's disease usually does not decrease.

Diagnostics

When making a diagnosis, a number of diseases whose symptoms and examination results are similar to CD should be excluded:

• appendicitis,
• diverticulitis,
• yersiniosis,
• intestinal tuberculosis,
• all types of infectious inflammation ( salmonellosis , pseudomembranous colitis ),
• ulcerative colitis,
• AIDS.

The correct diagnosis is usually established during laparotomy, X-ray examination, and irrigoscopy .

What does X-ray examination reveal?

With fluoroscopy (irrigoscopy), three stages of the disease can be established:

• Stage I (early changes). Characteristic signs are thickening and straightening of the walls due to edema; the presence of multiple superficial ulcers with a diameter of 0.1-0.2 cm, surrounded by an inflammatory shaft, unevenness, in some places, vagueness of the intestinal wall, the elasticity of the wall is preserved.
• Stage II (intermediate changes). The intestinal wall is significantly thickened, the width of the intestinal lumen is within normal limits, ulcerations, rigidity of the mesenteric edge, and nodular defects with a diameter of less than 1 cm are observed.
• Stage III (pronounced changes). As the process progresses, the leading radiological symptom becomes a narrowing of the affected area of ​​the intestine, which takes on the appearance of a cord. Characteristic spicule-like (needle-like) projections are often found. An important sign is the shortening of the affected areas of the small and large intestine, the walls are thickened and rigid.

Other types of CD research

In recent years, multidetector CT (computed tomography) and MRI (magnetic resonance imaging) have been increasingly used to diagnose Crohn's disease. These methods allow visualization of all parts of the intestine.

The new paradigm of patient examination includes its safety as a very important aspect when assessing the role of any diagnostic method. MRI, unlike CT, does not expose the human body to ionizing radiation, and therefore is the preferred method for assessing small intestinal disease, especially in young people.

Colonoscopy is used to examine the colon and terminal ileum, extending from 10 to 30 cm .

Diagnosis according to the Montreal classification

Sometimes the diagnosis of Crohn's disease is recorded by doctors using the Montreal classification. In this case it looks like this:

Crohn's disease: A2; L3; IN 1.

Below is a table of these designations.

Age at diagnosis	A1-under 16 years old, A2-from 17 to 40 years old, A3-over 40 years old
Localization	L1-in the ileum L2-in the colon, L3-in the ileum and colon, L4-isolated lesion of the upper gastrointestinal tract
Nature of the lesion	B1-non-stenotic, B2-stenotic, B3-penetrating, p-modifier, reflecting the presence of changes in the perianal area.

How to assess the severity of Crohn's disease?

The severity of Crohn's disease is assessed by the CD Activity Index (CAI).

• ABI greater than 450 indicates a severe course of the disease;
• more than 150, but less than 450 indicates an exacerbation;
• less than 150 – for remission.

Calculation of IABK

Index	Number of points	Coefficient
Number of bowel movements with loose or soft stools within 7 days	0-70	x2
Severity of abdominal pain over 7 days	0-21	x6
Well-being within 7 days	0-28	x6
number of extraintestinal manifestations	0-3	x30
Use of opiates for diarrhea	0-1	x4
Volumetric formations in the abdominal cavity	0-5	x10
Severity of blood loss: Ht men - 47, women - 42	-	6
Degree of weight loss	-	1

For symptomatic assessment of the activity of the inflammatory process in CD, the Best index is used.