eMedicine Specialties > Pediatrics: General Medicine > Gastroenterology

Colitis

Author: Jagvir Singh, MD, Director, Division of Pediatric Emergency Medicine, Lutheran General Hospital of Park Ridge
Contributor Information and Disclosures

Updated: Jun 17, 2009

Introduction

Background

Colitis is an inflammation of the colon. It may be associated with enteritis (inflammation of the intestine) and/or proctitis (inflammation of the rectum). Inflammatory bowel disease (IBD) is a generic term used to describe 2 idiopathic disorders that are associated with GI inflammation: Crohn disease (CD) and ulcerative colitis (UC). A study from Scotland reported a 3-fold rise in newly diagnosed CD from 1968-1983 and a 4.4-fold rise from 1968-1988. However, a consistent upward trend in cases of UC in the same period did not occur.

Pathophysiology

The pathophysiology of colitis differs because of various etiologies.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is common cause of colitis in newborns.

NEC appears to involve a final common pathway that includes the endogenous production of inflammatory mediators, such as endotoxin lipopolysaccharide, platelet-activating factor, tumor necrosis factor, and other cytokines,¹ that are involved in intestinal injury.

Hypoxic ischemia and aggressive enteral feedings are also associated in the pathogenesis of NEC. Varying degrees of mucosal and/or transmural necrosis of the intestine and colon are recognized. The distal ileum and proximal colon are most frequently involved; in severe cases, gangrene may involve the whole bowel from the rectum to the stomach. NEC presents with the gas accumulation in the submucosa of the bowel wall and progresses to necrosis leading to perforation of the bowel, peritonitis, and sepsis. Histological changes in NEC include mucosal edema, hemorrhage, coagulation necrosis, and mucosal ulceration.

Allergic colitis

In children aged 2 weeks to 1 year, the most common form of colitis is allergic colitis, which results from hypersensitivity commonly to cow's milk and soy milk. The so-called breast milk allergy is a status of food allergy induced in breastfed babies by heterologous proteins (typically cow's milk proteins) ingested by their mothers and appearing in their breast milk. The immunologic responses may vary from classic allergic mast cell activation to immune complex formation.

Pseudomembranous colitis

Pseudomembranous colitis is a form of inflammatory colitis characterized by the pathologic presence of pseudomembranes consisting of mucin, fibrin, necrotic cells, and polymorphonuclear leukocytes. This form of colitis is pathognomonic of infection by toxin-producing Clostridium difficile and develops as a result of altered normal microflora (usually by antibiotic therapy) that favors overgrowth and colonization of the intestine by Clostridium difficile and production of its toxins. Although every antibiotic has been reported to be associated with pseudomembranous colitis, clindamycin and amoxicillin are the antibiotics most frequently implicated in children.

Inflammatory bowel disease

IBD is an uncommon cause of chronic colitis in children but is becoming more frequent. The etiology is poorly understood.

UC is characterized by inflammation and ulceration confined to colonic mucosa. CD is manifested by transmural inflammation and granulomas affecting any segment of the GI tract, including the colon. UC invariably involves the rectum and extends proximally without skipping segments. In contrast, CD has discontinuous patchy involvement of the GI tract, involving the small bowel, ileum, and colon. Growth failure results from malabsorption and loss of proteins from inflammation and damage to the mucosa; it is 3 times more likely to occur in children with CD than in children with UC.

The diarrhea also results from mucosal damage, bile acid malabsorption, bacterial overgrowth, and protein exudation from mucosa. Extraintestinal manifestations, which are slightly more common in CD than in UC, result from bacterial products and inflammatory mediators (eg, cytokines, prostaglandins, reactive oxygen metabolites) entering and subsequently being deposited in various tissues and organs, such as eye (uveitis), skin (erythema nodosum), liver (cholangitis, hepatitis), and joints (arthritis).

Bacterial colitis

Bacterial colitis is the most common cause of colitis, particularly beyond the first year of life. It can be caused by bacterial, viral, and parasitic agents. The most common bacterial agents are Escherichia coli (enterohemorrhagic E coli [EHEC] and enteroinvasive E coli [EIEC]) and species of Shigella, Salmonella, Campylobacter, and Yersinia.

Salmonella infections are typically spread by the fecal-oral route; the outbreaks commonly are associated with contaminated eggs, dairy products, and meats. Gastric acid is usually lethal to the organism, but susceptibility to infection is increased with decreased GI motility, rapid emptying of the stomach postgastrectomy, a large quantity of ingested bacteria, malnutrition, antibiotic use, and achlorhydria. Salmonellae can penetrate the epithelial layer to the level of the lamina propria and evoke a leukocyte response. Salmonellae cause diarrhea by producing several toxins and prostaglandins, stimulating the active secretion of fluids and electrolytes.

Shigella species attach to binding sites on the surface of the intestinal mucosal cells. The organism penetrates and proliferates in the cell, which leads to cell destruction, produces mucosal ulcerations, and causes bleeding. Shigellae also elaborate the exotoxins that produce diarrhea.

E coli may produce diarrhea because of several characteristics. Pathologic strains have been classified as enteropathogenic, enterotoxic, enteroinvasive, enteroaggregative, enteroadherent, and enterohemorrhagic. EHEC, including O157:H7 and O26:H11, cause hemorrhagic colitis and systemic complications (eg, hemolytic uremic syndrome [HUS]). The risk of developing HUS after infection with E coli O157 is estimated to be 10-15% in children. In typical infectious colitis, the lamina propria of the large intestine is infiltrated by polymorphonuclear leukocytes. On the other hand, EIEC share almost identical pathogenetic mechanisms with Shigella.

Parasitic colitis

Entamoeba histolytica is the most common cause of parasitic colitis in the world. Transmission is through ingestion of trophozoites, usually from water contamination, and person-to-person transmission because of poor sanitation. Balantidium coli is a large ciliated protozoan that manifests very similar to amebiasis.

Viral colitis caused by cytomegalovirus infection

Colitis caused by cytomegalovirus (CMV) infection is a rare form of colitis that typically is found in immunocompromised patients, such as organ recipients who are receiving immunosuppressive treatment. It results in deep round ulcerations that have a tendency to bleed easily and profusely.

Ischemic colitis

Ischemic colitis is a form of vasculitis that results from inflammation and ischemia of colonic mucosa, which causes rectal bleeding and abdominal pain. This form of colitis is common in Henoch-Schönlein purpura (HSP), which is considered one of the collagen vascular diseases.

Frequency

United States

The onset of IBD commonly occurs during adolescence and young adulthood. The risk of IBD in family members of an affected individual is 7-22%; a child's risk of acquiring the disease is more than 35% if both parents have the disease.

• The prevalence of UC in the United States is 100-200 per 100,000 population.
• The incidence of CD is approximately 3-4 per 100,000 population, and the prevalence is 30-100 per 100,000 population.
• NEC affects 1-5% of patients admitting to neonatal ICUs.
• NEC may occur in 2-5% of infants with birthweights less than 1500 g.
• In the United States, the prevalence of amebiasis in high-risk groups is reported to be 1-4%.

International

The incidence UC is highest in northern European countries and the United States (15/100,000); incidence is lowest in Japan and South Africa (1/100,000).²

• A north-to-south gradient appears to be present, with higher incidence of both UC and CD in northern locations.
• The prevalence of amebic infections worldwide varies from 5-81%, with the highest frequency occurring in tropical climates.

Mortality/Morbidity

• Diarrheal diseases are some of the leading causes of morbidity and mortality in children worldwide, causing one billion episodes of illness and 3-5 million deaths annually.
• In the United States, 20-35 million episodes of diarrhea occur each year in the 16.5 million children who are younger than 5 years, resulting in 300-400 deaths.
• Medical treatment fails in 20% of patients who have NEC with pneumatosis intestinalis at diagnosis, resulting in a 9-25% mortality rate. The mortality rate of NEC is greater than 50% in infants with birthweights less than 1000 g.

Race

• The prevalence of IBD is increased among Jewish people of European Ashkenazi descent. A positive family history is the most consistent risk factor for children with IBD. HSP is common in white people.
• Food-allergic colitis is believed to be present in approximately 0.5% of all infants.

Sex

• HSP is common in males.

Age

• NEC is a disease of newborns, with low and very low birth weight preterm infants being particularly susceptible.
• Allergic colitis is the most common form of colitis during the first year of life.
• IBD is generally diagnosed in children aged 5-16 years. IBD has a bimodal distribution with an early onset at age 15-25 years and a second smaller peak at age 50-80 years.
• HSP occurs in school-aged children and young adults.³

Clinical

History

The following may be observed in patients with colitis:

• Necrotizing enterocolitis (NEC) occurs with wide spectrum of illness, from mild with only guaiac-positive stools to severe with peritonitis, perforation, shock, coagulopathy, and death. The onset is usually insidious, but illness may rapidly progress. The first sign is abdominal distention with gastric retention, emesis, and discomfort. Illness may progress to hemodynamic compromise. A plain film radiograph of the abdomen can assist in the diagnosis.
• Infants with allergic colitis present with blood and mucous in the stool, vomiting, and diarrhea after introduction of milk when they are aged approximately 1 week to 3 months. The syndrome is also known to occur in exclusively breast-fed infants, as a reaction to food allergens present in the mother's diet and appearing in the breast milk. The typical presentation of milk-protein sensitivity colitis is the acute onset of blood-streaked mucoid diarrheal stool in a well-appearing infant younger than 6 months. The infants do not appear sick or dehydrated, and weight gain is typically within normal limits.
• Pseudomembranous colitis usually presents with profuse watery or mucoid diarrhea, tenesmus, fever, abdominal cramps, and tenderness usually within one week of antibiotic therapy. The stools may be frankly bloody or guaiac-positive.
• Inflammatory bowel disease (IBD) is generally diagnosed in children aged 5-16 years. The onset of IBD, with Crohn disease (CD) or ulcerative colitis (UC), is usually insidious, consisting of growth failure, weight loss, diarrhea, and occult rectal bleeding.
  • Growth failure is more common in children with CD (35-88%) than in children with UC (6-12%). Weight loss has been reported in as many as 68% of children who are diagnosed with IBD.
  • UC tends to run a more complicated course in children than in adults. Abdominal pain and diarrhea, with or without occult blood, are the most common symptoms at presentation. The pain is frequently colicky and, in CD, may localize to the right lower quadrant or periumbilical area. Frank rectal bleeding occurs in fewer than 25% of all cases but is more common in UC than CD. Perianal disease, including fissures, skin tags, fistulae, and abscesses, occurs in 15% of children with CD and may precede the intestinal manifestations by several years, leading to a misdiagnosis that may include infectious colitis, iron deficiency anemia, juvenile rheumatoid arthritis, and growth disorders.
  • Arthralgias and arthritis are among the most frequent extraintestinal complaints of children with UC. The presence of ankylosing spondylitis is more consistent with a diagnosis of CD than UC. Pubertal development may be delayed or arrested in patients with active UC. Aphthous stomatitis is frequently present during the initial attack or relapse of UC. Renal calculi develop in 6% of patients, predominantly as uric acid in UC and as oxalate in CD. Ophthalmic complications (eg, uveitis, iritis, episcleritis) may be a sign of IBD or secondary to corticosteroid therapy in patients treated for IBD.
  • The disease is characterized as mild, moderate, or severe, depending on stool frequency, amount of abdominal tenderness, fever, and hemoglobin and albumin concentrations.
• Salmonellae may cause food-borne outbreaks, often in summer and fall. The child experiences abdominal cramps and nausea after an incubation period of 8-48 hours postingestion of a contaminated source, food or water. The stools are watery and may contain blood. Fever is noted in most children.
• Shigellae may cause asymptomatic infection, mild gastroenteritis, or bacillary dysentery. Bacillary dysentery begins suddenly with fever and abdominal pain, and diarrhea begins shortly thereafter. The stools are frequent, averaging of 10-12 daily, and they contain mucous and blood; tenesmus is common. The child has a fever, often in the range of 102-104°F (39-40°C). A shigellae infection occasionally produces CNS irritation and presents as seizure, even before other manifestations of the illness arise.
• Campylobacter enteritis is characterized by the abrupt onset of fever and abdominal pain, shortly followed by diarrhea. Temperature often remains normal in children younger than 3 months, but ranges up to 40°C in older children. Vomiting is uncommon. Two thirds of the children may have severe abdominal pain. The stools are watery and occur 2-20 times daily; they contain blood in 50-95% of cases.
• Yersinia enterocolitica infection presents with an abrupt onset of watery diarrhea that may contain blood. Most of the patients experience severe abdominal pain, which may be mistaken for appendicitis. Older children have a febrile response with a temperature from 99-104°F. Joint pain secondary to arthritis and rashes occur in 5-10% of patients with yersiniosis.
• Amebiasis is manifested clinically as dysenteric colitis, commonly presenting with bloody diarrhea, abdominal pain, and fever. B coli causes similar symptoms to amebiasis.
• Henoch-Schönlein purpura (HSP) is preceded by upper respiratory infection in one third to three fourths of patients. The patient presents with colicky abdominal pain, migratory arthritis affecting the larger joints, and a purpuric rash that is symmetrical and most noticeable over the extensor surfaces of the arms, legs, and buttocks.

Physical

• NEC may present with abdominal distention, tenderness, and guarding. The infant may develop hypotension, tachycardia, tachypnea, hypoxia, shock, disseminated intravascular coagulation (DIC), and cardiopulmonary arrest. The stool may have frank blood or may be heme-guaiac positive.
• Allergic colitis presents with blood and mucous in the stool. Children are usually well appearing; however, uncommonly, the colitis is severe, and the children may become anemic and present with failure to thrive.
• Pseudomembranous colitis presents with diarrhea with frank blood or a guaiac-positive stool. An abdominal examination may elicit tenderness. Signs of perforation, peritonitis, and toxic megacolon may be present.
• IBD may present with pallor, tachycardia, abdominal tenderness, and blood in the stool. The child may present with an elevated temperature, weight loss, and dehydration. The presence of abdominal distention with decreased or absent bowel sounds is indicative of actual or impending perforation. Rarely, CD causes intestinal obstruction. Toxic megacolon is a life-threatening complication of UC and CD. Toxic megacolon almost always involves the transverse colon and may present with ileus, peritonitis secondary to perforation, and sepsis.
• Amebiasis may present with temperature elevation, hematochezia, abdominal tenderness, or complications such as liver abscess, colonic perforation, and peritonitis.
• HSP presents with a purpuric symmetric rash commonly over legs, buttocks, and arms. Asymptomatic microhematuria occurs in 80% of affected patients. The child may have hypertension, proteinuria, and hematochezia. Joint swelling may be present.

Causes

• Inflammation of the colon can be caused by infection, hypersensitivity to various allergens, ischemia, vasculitis, or several drugs.
• The cause of colitis in IBD is unknown, but recent studies have identified a gene (NOD2) involved in at least 20% of cases of Crohn disease. This gene is involved in the regulation of the epithelial response to bacterial antigens, thus stressing the role of bacteria in the pathogenesis of IBD. Evidence suggests a genetic predisposition to IBD, including ethnic differences, family aggregation, concordance rates in twins, chromosomal linkage, and genetic syndromes associated with IBD. The lack of total concordance of disease among monozygotic twins and other differences support a role for cofactors in the development of IBD.
• In the United States, bacterial and viral infections are very common causes of colitis, whereas in developing countries, parasitic infections are very common causes.

• Search for CME/CE on This Topic »

• Pseudomembranous Colitis, Surgical Treatment (General Surgery)
• Pseudomembranous Colitis (Infectious Diseases)
• Clostridium Difficile Colitis (Gastroenterology)
• Collagenous and Lymphocytic Colitis (Gastroenterology)

• Good Long-Term Outcomes of Surgery in Children With Ulcerative Colitis
• Budesonide Effective for Colitis Maintenance Therapy
• Once Daily Mesalazine Effective in Active Ulcerative Colitis: Study

• Budesonide Is Effective in Treating Lymphocytic Colitis: A Randomized Double-Blind Placebo-Controlled Study
• Therapy of Ulcerative Colitis: State of the Art
• Review Article: New Drug Formulations, Chemical Entities and Therapeutic Approaches for the Management of Ulcerative Colitis