INFLAMMATORY BOWEL DISEASE
Speaking Up About an Uncomfortable Condition
By Jane E. Brody : NY Times : May 26, 2014
Bowels, especially those that don’t function properly, are not a popular topic of conversation. Most of the 1.4 million Americans with inflammatory bowel disease — Crohn’s disease or ulcerative colitis — suffer in silence.
But scientists are making exciting progress in understanding the causes of these conditions and in developing more effective therapies. And affected individuals have begun to speak up to let others know that they are not alone.
In Crohn’s disease, the immune system attacks cells in the digestive tract, most often the end of the small intestine and first part of the colon, or large intestine. Sufferers may experience bouts of abdominal pain, cramps and diarrhea, often accompanied by poor appetite, fatigue and anxiety.
“You don’t go anywhere without checking where the bathroom is and how many stalls it has,” said Dr. R. Balfour Sartor, a gastroenterologist at the University of North Carolina School of Medicine and a patient himself. “The fear of incontinence is huge.”
Neither Crohn’s disease nor its less common relative ulcerative colitis, which affects only the large intestine, is curable (except, in the latter instance, by removing the entire colon). But research into what predisposes people to develop these conditions has resulted in more effective treatments and has suggested new ways to prevent the diseases in people who are genetically susceptible.
Two concurrent avenues of high-powered research are supported by the Crohn’s and Colitis Foundation of America. One is the C.C.F.A. Genetics Initiative, in which scientists are exploring more than 100 genetic factors now known to influence the risk of developing an inflammatory bowel disease, or I.B.D.
The other research effort, the C.C.F.A. Microbiome Initiative, has so far identified 14 different bacterial metabolic factors associated with the diseases.
By combining findings from the two initiatives, experts now know that certain genes affect the types of bacteria living in the gut; in turn, these bacteria influence the risk of getting an inflammatory bowel disease.
Genes identified thus far appear to account for about 30 percent of the risk of developing an I.B.D., according to Dr. Sartor, who is the chief medical adviser of the foundation. Studies of twins underscore the role of genetics. When one identical twin has Crohn’s disease, the other has a 50 percent chance of also developing it.
In the general population, the risk among siblings of a Crohn’s patient is only 5 percent.
Many people carry genes linked to either Crohn’s or ulcerative colitis, but only some of them become ill. Environmental factors that interact with susceptibility genes also play critical roles.
Strong clues to these factors are emerging from a distressing fact: The incidence of I.B.D. is rising significantly both here and in other parts of the world, Dr. Ramnik J. Xavier, chief of gastroenterology at Massachusetts General Hospital in Boston, said in an interview.
“There’s been a huge uptick in China and India as these countries move more toward a Western lifestyle and adopt Western work and dietary patterns,” Dr. Xavier said. “I.B.D. cases are now skyrocketing in well-to-do areas of China.”
And when people migrate from a low-incidence area to a higher one like the United States, the risk of developing an I.B.D. rises greatly among their children. ‘This clearly shows there’s an environmental impact that we think is multifactorial,” Dr. Sartor said in an interview.
“Diet is one obvious factor that affects both the composition of the gut biota and also its function,” he said, referring to the microorganisms that inhabit the gut. “Bacteria eat what we eat, and every bacterium has certain food preferences.”
Diet influences the types and balance of microbes in the gut, and different microbes produce substances that are either protective or harmful. For example, Dr. Sartor said, “Certain bacteria that can metabolize the fiber in certain vegetables and grains produce short-chain fatty acids that are believed to protect the gut. They inhibit inflammation and activate immune responses that stimulate recovery from cell injury.”
Another major contributor to the rise in Crohn’s disease in particular is the widespread, often inappropriate use of antibiotics, Dr. Sartor said.
“Early exposure to antibiotics, especially during the first 15 months of life, increases the risk of developing Crohn’s disease, though not ulcerative colitis,” he said. “If there’s a family history of I.B.D., particularly Crohn’s disease, antibiotics should be used only for a documented bacterial infection like strep throat or bacterial meningitis.
“And when antibiotics are needed, probiotics can be used during and afterward to minimize their effect and restore the normal bacterial population of the gut.”
Dr. Sartor also noted that early exposure to common viruses and bacteria can strengthen the immune system and keep it from attacking normal tissues.
“My advice to parents and grandparents is, ‘Let them eat dirt,’ ” he said.
Dr. Sartor has lived with Crohn’s disease for 43 years and for the most part has managed to keep flare-ups at bay with a proper diet, medications and daily probiotics.
He also suggests that those with a family history of I.B.D. avoid taking nonsteroidal anti-inflammatory drugs like aspirin, ibuprofen and naproxen, which block the action of protective substances in the gut and can cause ulcers in the lower intestine and the stomach. Acetaminophen is safer, he said.
Many patients say undue stress can cause flare-ups of an I.B.D. And a new study of 3,150 adults with Crohn’s, presented at a recent scientific meeting by Lawrence S. Gaines, a psychologist at Vanderbilt University, suggests that depression — feeling sad, helpless, hopeless and worthless — increases the risk of active disease a year later.
By Jane E. Brody : NY Times : May 26, 2014
Bowels, especially those that don’t function properly, are not a popular topic of conversation. Most of the 1.4 million Americans with inflammatory bowel disease — Crohn’s disease or ulcerative colitis — suffer in silence.
But scientists are making exciting progress in understanding the causes of these conditions and in developing more effective therapies. And affected individuals have begun to speak up to let others know that they are not alone.
In Crohn’s disease, the immune system attacks cells in the digestive tract, most often the end of the small intestine and first part of the colon, or large intestine. Sufferers may experience bouts of abdominal pain, cramps and diarrhea, often accompanied by poor appetite, fatigue and anxiety.
“You don’t go anywhere without checking where the bathroom is and how many stalls it has,” said Dr. R. Balfour Sartor, a gastroenterologist at the University of North Carolina School of Medicine and a patient himself. “The fear of incontinence is huge.”
Neither Crohn’s disease nor its less common relative ulcerative colitis, which affects only the large intestine, is curable (except, in the latter instance, by removing the entire colon). But research into what predisposes people to develop these conditions has resulted in more effective treatments and has suggested new ways to prevent the diseases in people who are genetically susceptible.
Two concurrent avenues of high-powered research are supported by the Crohn’s and Colitis Foundation of America. One is the C.C.F.A. Genetics Initiative, in which scientists are exploring more than 100 genetic factors now known to influence the risk of developing an inflammatory bowel disease, or I.B.D.
The other research effort, the C.C.F.A. Microbiome Initiative, has so far identified 14 different bacterial metabolic factors associated with the diseases.
By combining findings from the two initiatives, experts now know that certain genes affect the types of bacteria living in the gut; in turn, these bacteria influence the risk of getting an inflammatory bowel disease.
Genes identified thus far appear to account for about 30 percent of the risk of developing an I.B.D., according to Dr. Sartor, who is the chief medical adviser of the foundation. Studies of twins underscore the role of genetics. When one identical twin has Crohn’s disease, the other has a 50 percent chance of also developing it.
In the general population, the risk among siblings of a Crohn’s patient is only 5 percent.
Many people carry genes linked to either Crohn’s or ulcerative colitis, but only some of them become ill. Environmental factors that interact with susceptibility genes also play critical roles.
Strong clues to these factors are emerging from a distressing fact: The incidence of I.B.D. is rising significantly both here and in other parts of the world, Dr. Ramnik J. Xavier, chief of gastroenterology at Massachusetts General Hospital in Boston, said in an interview.
“There’s been a huge uptick in China and India as these countries move more toward a Western lifestyle and adopt Western work and dietary patterns,” Dr. Xavier said. “I.B.D. cases are now skyrocketing in well-to-do areas of China.”
And when people migrate from a low-incidence area to a higher one like the United States, the risk of developing an I.B.D. rises greatly among their children. ‘This clearly shows there’s an environmental impact that we think is multifactorial,” Dr. Sartor said in an interview.
“Diet is one obvious factor that affects both the composition of the gut biota and also its function,” he said, referring to the microorganisms that inhabit the gut. “Bacteria eat what we eat, and every bacterium has certain food preferences.”
Diet influences the types and balance of microbes in the gut, and different microbes produce substances that are either protective or harmful. For example, Dr. Sartor said, “Certain bacteria that can metabolize the fiber in certain vegetables and grains produce short-chain fatty acids that are believed to protect the gut. They inhibit inflammation and activate immune responses that stimulate recovery from cell injury.”
Another major contributor to the rise in Crohn’s disease in particular is the widespread, often inappropriate use of antibiotics, Dr. Sartor said.
“Early exposure to antibiotics, especially during the first 15 months of life, increases the risk of developing Crohn’s disease, though not ulcerative colitis,” he said. “If there’s a family history of I.B.D., particularly Crohn’s disease, antibiotics should be used only for a documented bacterial infection like strep throat or bacterial meningitis.
“And when antibiotics are needed, probiotics can be used during and afterward to minimize their effect and restore the normal bacterial population of the gut.”
Dr. Sartor also noted that early exposure to common viruses and bacteria can strengthen the immune system and keep it from attacking normal tissues.
“My advice to parents and grandparents is, ‘Let them eat dirt,’ ” he said.
Dr. Sartor has lived with Crohn’s disease for 43 years and for the most part has managed to keep flare-ups at bay with a proper diet, medications and daily probiotics.
He also suggests that those with a family history of I.B.D. avoid taking nonsteroidal anti-inflammatory drugs like aspirin, ibuprofen and naproxen, which block the action of protective substances in the gut and can cause ulcers in the lower intestine and the stomach. Acetaminophen is safer, he said.
Many patients say undue stress can cause flare-ups of an I.B.D. And a new study of 3,150 adults with Crohn’s, presented at a recent scientific meeting by Lawrence S. Gaines, a psychologist at Vanderbilt University, suggests that depression — feeling sad, helpless, hopeless and worthless — increases the risk of active disease a year later.
New Therapies for a Debilitating Condition
By Jane E. Brody : NY Times : June 2, 2014
Decades ago, I met a surprisingly quiet, withdrawn young man. Surprising because I knew his bright, vibrant wife and wondered what had attracted her to him. He barely participated in conversations even at friendly family gatherings.
Some years later, the same man seemed to have undergone a personality transplant. He was forthright and funny, intelligent and interesting. I asked a mutual friend what could have accounted for the apparent transformation.
The answer: surgical removal of his chronically inflamed colon to treat ulcerative colitis. Once free of painful abdominal cramps, persistent diarrhea, fatigue, nausea and the depression and anxiety that can accompany these symptoms, he came to life. Even having to cope with a colostomy bag did not dampen his newly awakened spirit.
Today, this rather draconian treatment is reserved for the very few patients with inflammatory bowel disease — Crohn’s and ulcerative colitis — whose debilitating symptoms don’t respond to a growing number of less invasive modern therapies.
Although many people with chronically inflamed bowels still have surgery, it is nearly always less aggressive, rarely requiring an external pouch to replace a surgically removed colon and rectum.
Today in 98 percent of patients with ulcerative colitis in whom the colon must be removed, it is replaced by an internal pouch, creating a reservoir for stool that is sutured directly to the rectal canal, said Dr. R. Balfour Sartor, chief medical adviser to the Crohn’s and Colitis Foundation of America.
“This approach decreases urgency, enabling patients to defer the need to evacuate, and reduces the number of stools per day,” Dr. Sartor said in an interview.
Inflammatory bowel diseases afflict 1.4 million Americans, typically starting in the teenage years and lasting a lifetime. But treatments for these chronic conditions are being transformed, spurred by the decoding of the human genome and a growing understanding of the balance of microbes in the gut and why it goes awry in some people.
As with operative changes for ulcerative colitis, in recent decades, surgery for Crohn’s disease has become less disruptive of normal digestive function. Instead of removing diseased sections of the intestine, Crohn’s patients can have a procedure called strictureplasty, better preserving the body’s ability to absorb nutrients. Strictureplasty involves cutting the diseased area at its midpoint, stacking the two pieces on top of each other, then cutting and reconnecting them lengthwise.
The technique, known as Michalessi strictureplasty for the Weill Cornell surgeon Dr. Fabrizio Michalessi, has been shown to encourage regression of the disease in the treated area. “Surgery doesn’t cure Crohn’s,” Dr. Sartor said, “but this technique preserves most of the natural function of the small intestine, where nutrients are absorbed.”
Dr. Ellen J. Scherl, gastroenterologist at Weill Cornell Medical Center in New York, emphasized in an interview that “surgery is a therapy, not a failure of therapy.”
She added, “If doctors persist with medical therapy to avoid surgery, they may be subjecting patients to chronic flare-ups.”
At the same time, however, improved medical remedies are fast emerging. Experts in inflammatory bowel disease are working on treatments based on a patient’s genetic makeup, an approach now increasingly used to treat cancer.
Dr. Ramnik J. Xavier, chief of gastroenterology at Massachusetts General Hospital in Boston, said that after determining the genomic regions associated with inflammatory bowel diseases (163 genes have been linked to the ailments), “we’re now looking individually to identify certain genes that affect inflammation and the failure of ulcers to heal.”
There are also genetic changes that protect the gut, Dr. Xavier said, and targeted molecules could be designed to both treat the disease and prevent relapses.
“Ulcerative colitis and Crohn’s are in many ways the poster child for which sequencing the genome is having a tremendous impact,” Dr. Xavier said in an interview.
Equally important to improved treatment has been understanding how environmental factors like diet and antibiotics can disrupt the balance of microbes in the gut. Some bacteria are protective and keep the gut healthy, while others result in chronic inflammation.
“Antibiotics, which alter the gut microbiome, may be helpful or not,” Dr. Scherl noted. Tailor-making antibiotics that attack only harmful bacteria could give protective microbes a chance to dominate. And altering the diet to deny harmful microbes the nutrients they prefer can curb inflammation.
Dr. Scherl said that sugars, other carbohydrates and fats can lead to uncontrolled inflammation in the gut of people genetically predisposed to inflammatory bowel diseases. When a flare-up occurs, she said patients “must step back and eat simpler food — a so-called white diet — until the inflammation subsides.
Dr. Sandra C. Kim, pediatric gastroenterologist at Nationwide Children’s Hospital in Columbus, Ohio, treats flare-ups in children with what is called an elemental diet, involving a liquid in which the nutrients are completely broken down. The diet deprives harmful bacteria in the gut of the nutrients they need to produce substances that foster inflammation.
Although Dr. Kim acknowledges that the diet is not easy to stick to, when pursued for eight to 12 it can induce remission of the disease, reduce the risk of relapse and enable the child to grow normally.
Another new approach aims at gut-specific transport of inflammatory cells from the blood into the gut. The Food and Drug Administration just approved a drug called vedolizumab, which blocks the movement of those cells.
“This is a completely new strategy for treating Crohn’s and ulcerative colitis,” Dr. James D. Lewis, professor in the gastroenterology division at the University of Pennsylvania Perelman School of Medicine, said in an interview.
Perhaps most important for people with an inflammatory bowel disease, Dr. Scherl said, is to be cared for by a specialist “who understands its complexities and nuances and listens to patients who are living with it.”
By Jane E. Brody : NY Times : June 2, 2014
Decades ago, I met a surprisingly quiet, withdrawn young man. Surprising because I knew his bright, vibrant wife and wondered what had attracted her to him. He barely participated in conversations even at friendly family gatherings.
Some years later, the same man seemed to have undergone a personality transplant. He was forthright and funny, intelligent and interesting. I asked a mutual friend what could have accounted for the apparent transformation.
The answer: surgical removal of his chronically inflamed colon to treat ulcerative colitis. Once free of painful abdominal cramps, persistent diarrhea, fatigue, nausea and the depression and anxiety that can accompany these symptoms, he came to life. Even having to cope with a colostomy bag did not dampen his newly awakened spirit.
Today, this rather draconian treatment is reserved for the very few patients with inflammatory bowel disease — Crohn’s and ulcerative colitis — whose debilitating symptoms don’t respond to a growing number of less invasive modern therapies.
Although many people with chronically inflamed bowels still have surgery, it is nearly always less aggressive, rarely requiring an external pouch to replace a surgically removed colon and rectum.
Today in 98 percent of patients with ulcerative colitis in whom the colon must be removed, it is replaced by an internal pouch, creating a reservoir for stool that is sutured directly to the rectal canal, said Dr. R. Balfour Sartor, chief medical adviser to the Crohn’s and Colitis Foundation of America.
“This approach decreases urgency, enabling patients to defer the need to evacuate, and reduces the number of stools per day,” Dr. Sartor said in an interview.
Inflammatory bowel diseases afflict 1.4 million Americans, typically starting in the teenage years and lasting a lifetime. But treatments for these chronic conditions are being transformed, spurred by the decoding of the human genome and a growing understanding of the balance of microbes in the gut and why it goes awry in some people.
As with operative changes for ulcerative colitis, in recent decades, surgery for Crohn’s disease has become less disruptive of normal digestive function. Instead of removing diseased sections of the intestine, Crohn’s patients can have a procedure called strictureplasty, better preserving the body’s ability to absorb nutrients. Strictureplasty involves cutting the diseased area at its midpoint, stacking the two pieces on top of each other, then cutting and reconnecting them lengthwise.
The technique, known as Michalessi strictureplasty for the Weill Cornell surgeon Dr. Fabrizio Michalessi, has been shown to encourage regression of the disease in the treated area. “Surgery doesn’t cure Crohn’s,” Dr. Sartor said, “but this technique preserves most of the natural function of the small intestine, where nutrients are absorbed.”
Dr. Ellen J. Scherl, gastroenterologist at Weill Cornell Medical Center in New York, emphasized in an interview that “surgery is a therapy, not a failure of therapy.”
She added, “If doctors persist with medical therapy to avoid surgery, they may be subjecting patients to chronic flare-ups.”
At the same time, however, improved medical remedies are fast emerging. Experts in inflammatory bowel disease are working on treatments based on a patient’s genetic makeup, an approach now increasingly used to treat cancer.
Dr. Ramnik J. Xavier, chief of gastroenterology at Massachusetts General Hospital in Boston, said that after determining the genomic regions associated with inflammatory bowel diseases (163 genes have been linked to the ailments), “we’re now looking individually to identify certain genes that affect inflammation and the failure of ulcers to heal.”
There are also genetic changes that protect the gut, Dr. Xavier said, and targeted molecules could be designed to both treat the disease and prevent relapses.
“Ulcerative colitis and Crohn’s are in many ways the poster child for which sequencing the genome is having a tremendous impact,” Dr. Xavier said in an interview.
Equally important to improved treatment has been understanding how environmental factors like diet and antibiotics can disrupt the balance of microbes in the gut. Some bacteria are protective and keep the gut healthy, while others result in chronic inflammation.
“Antibiotics, which alter the gut microbiome, may be helpful or not,” Dr. Scherl noted. Tailor-making antibiotics that attack only harmful bacteria could give protective microbes a chance to dominate. And altering the diet to deny harmful microbes the nutrients they prefer can curb inflammation.
Dr. Scherl said that sugars, other carbohydrates and fats can lead to uncontrolled inflammation in the gut of people genetically predisposed to inflammatory bowel diseases. When a flare-up occurs, she said patients “must step back and eat simpler food — a so-called white diet — until the inflammation subsides.
Dr. Sandra C. Kim, pediatric gastroenterologist at Nationwide Children’s Hospital in Columbus, Ohio, treats flare-ups in children with what is called an elemental diet, involving a liquid in which the nutrients are completely broken down. The diet deprives harmful bacteria in the gut of the nutrients they need to produce substances that foster inflammation.
Although Dr. Kim acknowledges that the diet is not easy to stick to, when pursued for eight to 12 it can induce remission of the disease, reduce the risk of relapse and enable the child to grow normally.
Another new approach aims at gut-specific transport of inflammatory cells from the blood into the gut. The Food and Drug Administration just approved a drug called vedolizumab, which blocks the movement of those cells.
“This is a completely new strategy for treating Crohn’s and ulcerative colitis,” Dr. James D. Lewis, professor in the gastroenterology division at the University of Pennsylvania Perelman School of Medicine, said in an interview.
Perhaps most important for people with an inflammatory bowel disease, Dr. Scherl said, is to be cared for by a specialist “who understands its complexities and nuances and listens to patients who are living with it.”
What is IBD?
Inflammatory Bowel Diseases (IBD) is a broad term that describes conditions with chronic or recurring immune response and inflammation of the gastrointestinal tract. The two most common inflammatory bowel diseases are ulcerative colitis and Crohn’s disease.
Both illnesses have one strong feature in common. They are marked by an abnormal response by the body’s immune system. Normally, the immune cells protect the body from infection. In people with IBD, however, the immune system mistakes food, bacteria, and other materials in the intestine for foreign substances and it attacks the cells of the intestines. In the process, the body sends white blood cells into the lining of the intestines where they produce chronic inflammation. When this happens, the patient experiences the symptoms of IBD.
Neither ulcerative colitis nor Crohn's disease should be confused with irritable bowel syndrome (IBS), a disorder that affects the motility (muscle contractions) of the colon. Sometimes called "spastic colon" or "nervous colitis," IBS is not characterized by intestinal inflammation. It is, therefore, a much less serious disease than ulcerative colitis or Crohn’s disease. IBS bears no direct relationship to either ulcerative colitis or Crohn's disease.
About Crohn’s Disease
Crohn’s disease is a condition of chronic inflammation potentially involving any location of the gastrointestinal tract, but it frequently affects the end of the small bowel and the beginning of the large bowel. In Crohn's disease, all layers of the intestine may be involved and there can be normal healthy bowel between patches of diseased bowel.
Symptoms include persistent diarrhea (loose, watery, or frequent bowel movements), cramping abdominal pain, fever, and, at times, rectal bleeding. Loss of appetite and weight loss also may occur. However, the disease is not always limited to the gastrointestinal tract; it can also affect the joints, eyes, skin, and liver. Fatigue is another common complaint.
The most common complication of Crohn’s disease is blockage of the intestine due to swelling and scar tissue. Symptoms of blockage include cramping pain, vomiting, and bloating. Another complication is sores or ulcers within the intestinal tract. Sometimes these deep ulcers turn into tracts—called fistulas. In 30% of people with Crohn's disease, these fistulas become infected. Patients may also develop a shortage of proteins, calories, or vitamins. They generally do not develop unless the disease is severe and of long duration. Until recently an increased risk of cancer was thought to exist mainly for ulcerative colitis patients, but it is now known that Crohn’s patients have an increased risk of colon cancer as well.
The five groups of drugs used to treat Crohn’s disease today are aminosalicylates (5-ASA), steroids, immune modifiers (azathioprine, 6-MP, and methotrexate), antibiotics (metronidazole, ampicillin, ciprofloxin, others), and biologic therapy (inflixamab). Two-thirds to three-quarters of patients with Crohn's disease will require surgery at some point during their lives. Surgery becomes necessary in Crohn's disease when medications can no longer control the symptoms.
About Ulcerative Colitis
Ulcerative colitis is a chronic gastrointestinal disorder that is limited to the large bowel (the colon). Ulcerative colitis does not affect all layers of the bowel, but only affects the top layers of the colon in an even and continuous distribution. The first symptom of ulcerative colitis is a progressive loosening of the stool. The stool is generally bloody and may be associated with cramping abdominal pain and severe urgency to have a bowel movement. The diarrhea may begin slowly or quite suddenly. Loss of appetite and subsequent weight loss are common, as is fatigue. In cases of severe bleeding, anemia may also occur. In addition, there may be skin lesions, joint pain, eye inflammation, and liver disorders. Children with ulcerative colitis may fail to develop or grow properly.
Approximately half of all patients with ulcerative colitis have mild symptoms. However, others may suffer from severe abdominal cramping, bloody diarrhea, nausea, and fever. The symptoms of ulcerative colitis do tend to come and go, with fairly long periods in between flare-ups in which patients may experience no distress at all.
Complications of ulcerative colitis are less frequent than in Crohn’s disease. Complications can include bleeding from deep ulcerations, rupture of the bowel, or failure of the patient to respond to the usual medical treatments. Another complication is severe abdominal bloating. Patients with ulcerative colitis are at increased risk of colon cancer.
The four major classes of medication used today to treat ulcerative colitis are aminosalicylates (5-ASA), steroids, immune modifiers (azathioprine, 6-MP, and methotrexate), and antibiotics (metronidazole, ampicillin, ciprofloxin, others). In one-quarter to one-third of patients with ulcerative colitis, medical therapy is not completely successful or complications arise. Under these circumstances, surgery may be considered. This operation involves the removal of the colon (colectomy). Unlike Crohn's disease, which can recur after surgery, ulcerative colitis is "cured" once the colon is removed.
Epidemiology of the IBD
The peak age of onset for IBD is 15 to 30 years old, although it may occur at any age. About 10% of cases occur in individuals younger than 18 years. Ulcerative colitis is slightly more common in males, whereas Crohn’s disease is marginally more frequent in women. IBD occurs more in people of Caucasian and Ashkenazic Jewish origin than in other racial and ethnic subgroups. In the past, it was thought that IBD occurred less frequently in ethnic or racial minority groups compared with whites. But, previously noted racial and ethnic differences seem to be narrowing.
Precise incidence and prevalence of Crohn’s disease and ulcerative colitis have been limited by (1) a lack of gold standard criteria for diagnosis; (2) inconsistent case ascertainment; and (3) disease misclassification. The data that does exist suggest that the worldwide incidence rate of ulcerative colitis varies greatly between 0.5–24.5/100,000 persons, while that of Crohn’s disease varies between 0.1–16/100,000 persons worldwide, with the prevalence rate of IBD reaching up to 396/100,000 persons. It is estimated that as many as 1.4 million persons in the United States suffer from these diseases.
The etiology of IBD is unknown but is thought to involve genetic, immunologic, and environmental factors as evidenced by the following:
Inflammatory Bowel Diseases (IBD) is a broad term that describes conditions with chronic or recurring immune response and inflammation of the gastrointestinal tract. The two most common inflammatory bowel diseases are ulcerative colitis and Crohn’s disease.
Both illnesses have one strong feature in common. They are marked by an abnormal response by the body’s immune system. Normally, the immune cells protect the body from infection. In people with IBD, however, the immune system mistakes food, bacteria, and other materials in the intestine for foreign substances and it attacks the cells of the intestines. In the process, the body sends white blood cells into the lining of the intestines where they produce chronic inflammation. When this happens, the patient experiences the symptoms of IBD.
Neither ulcerative colitis nor Crohn's disease should be confused with irritable bowel syndrome (IBS), a disorder that affects the motility (muscle contractions) of the colon. Sometimes called "spastic colon" or "nervous colitis," IBS is not characterized by intestinal inflammation. It is, therefore, a much less serious disease than ulcerative colitis or Crohn’s disease. IBS bears no direct relationship to either ulcerative colitis or Crohn's disease.
About Crohn’s Disease
Crohn’s disease is a condition of chronic inflammation potentially involving any location of the gastrointestinal tract, but it frequently affects the end of the small bowel and the beginning of the large bowel. In Crohn's disease, all layers of the intestine may be involved and there can be normal healthy bowel between patches of diseased bowel.
Symptoms include persistent diarrhea (loose, watery, or frequent bowel movements), cramping abdominal pain, fever, and, at times, rectal bleeding. Loss of appetite and weight loss also may occur. However, the disease is not always limited to the gastrointestinal tract; it can also affect the joints, eyes, skin, and liver. Fatigue is another common complaint.
The most common complication of Crohn’s disease is blockage of the intestine due to swelling and scar tissue. Symptoms of blockage include cramping pain, vomiting, and bloating. Another complication is sores or ulcers within the intestinal tract. Sometimes these deep ulcers turn into tracts—called fistulas. In 30% of people with Crohn's disease, these fistulas become infected. Patients may also develop a shortage of proteins, calories, or vitamins. They generally do not develop unless the disease is severe and of long duration. Until recently an increased risk of cancer was thought to exist mainly for ulcerative colitis patients, but it is now known that Crohn’s patients have an increased risk of colon cancer as well.
The five groups of drugs used to treat Crohn’s disease today are aminosalicylates (5-ASA), steroids, immune modifiers (azathioprine, 6-MP, and methotrexate), antibiotics (metronidazole, ampicillin, ciprofloxin, others), and biologic therapy (inflixamab). Two-thirds to three-quarters of patients with Crohn's disease will require surgery at some point during their lives. Surgery becomes necessary in Crohn's disease when medications can no longer control the symptoms.
About Ulcerative Colitis
Ulcerative colitis is a chronic gastrointestinal disorder that is limited to the large bowel (the colon). Ulcerative colitis does not affect all layers of the bowel, but only affects the top layers of the colon in an even and continuous distribution. The first symptom of ulcerative colitis is a progressive loosening of the stool. The stool is generally bloody and may be associated with cramping abdominal pain and severe urgency to have a bowel movement. The diarrhea may begin slowly or quite suddenly. Loss of appetite and subsequent weight loss are common, as is fatigue. In cases of severe bleeding, anemia may also occur. In addition, there may be skin lesions, joint pain, eye inflammation, and liver disorders. Children with ulcerative colitis may fail to develop or grow properly.
Approximately half of all patients with ulcerative colitis have mild symptoms. However, others may suffer from severe abdominal cramping, bloody diarrhea, nausea, and fever. The symptoms of ulcerative colitis do tend to come and go, with fairly long periods in between flare-ups in which patients may experience no distress at all.
Complications of ulcerative colitis are less frequent than in Crohn’s disease. Complications can include bleeding from deep ulcerations, rupture of the bowel, or failure of the patient to respond to the usual medical treatments. Another complication is severe abdominal bloating. Patients with ulcerative colitis are at increased risk of colon cancer.
The four major classes of medication used today to treat ulcerative colitis are aminosalicylates (5-ASA), steroids, immune modifiers (azathioprine, 6-MP, and methotrexate), and antibiotics (metronidazole, ampicillin, ciprofloxin, others). In one-quarter to one-third of patients with ulcerative colitis, medical therapy is not completely successful or complications arise. Under these circumstances, surgery may be considered. This operation involves the removal of the colon (colectomy). Unlike Crohn's disease, which can recur after surgery, ulcerative colitis is "cured" once the colon is removed.
Epidemiology of the IBD
The peak age of onset for IBD is 15 to 30 years old, although it may occur at any age. About 10% of cases occur in individuals younger than 18 years. Ulcerative colitis is slightly more common in males, whereas Crohn’s disease is marginally more frequent in women. IBD occurs more in people of Caucasian and Ashkenazic Jewish origin than in other racial and ethnic subgroups. In the past, it was thought that IBD occurred less frequently in ethnic or racial minority groups compared with whites. But, previously noted racial and ethnic differences seem to be narrowing.
Precise incidence and prevalence of Crohn’s disease and ulcerative colitis have been limited by (1) a lack of gold standard criteria for diagnosis; (2) inconsistent case ascertainment; and (3) disease misclassification. The data that does exist suggest that the worldwide incidence rate of ulcerative colitis varies greatly between 0.5–24.5/100,000 persons, while that of Crohn’s disease varies between 0.1–16/100,000 persons worldwide, with the prevalence rate of IBD reaching up to 396/100,000 persons. It is estimated that as many as 1.4 million persons in the United States suffer from these diseases.
The etiology of IBD is unknown but is thought to involve genetic, immunologic, and environmental factors as evidenced by the following:
- The greatest relative risk of IBD disease is found among first-degree relatives, suggesting a strong genetic component.
- Smoking is one of the more notable environmental factors. Ulcerative colitis is more prevalent among ex-smokers and nonsmokers, whereas Crohn’s disease is more prevalent among smokers.
- There have been three studies outside of the United States that specifically examined the relationship between socioeconomic factors and IBD. One study found both ulcerative colitis and Crohn’s disease more prevalent in white collar compared with blue-collar occupations.3 Bernstein (2001) found Crohn's disease and ulcerative colitis less common in higher SES groups and Li (2009) found a minor association between specific occupations and IBD in a hospital-based study. This relationship should be further investigated in a U.S. population.
- IBD is more common in developed countries. There is a noted north- to- south variation and higher frequency in urban communities compared with rural areas. These observations suggest that urbanization is a potential contributing factor. It is postulated that this is the result of “westernization” of lifestyle, such as changes in diet, smoking, variances in exposure to sunlight, pollution, and industrial chemicals.
- Other factors such as diet, oral contraceptives, perinatal and childhood infections, or atypical mycobacterial infections have been suggested but not proven to play a role in expression of IBD.
