Children Digestive Tract
The gastrointestinal tract is a sensing, reactive device that monitors the material flowing through it. Symptoms arising from this system provide information about its dysfunction. Seven basic symptoms signal gastrointestinal tract displeasure with food choices - nausea, heartburn, vomiting, bloating, pain, constipation and diarrhea.
Parents need to know two basic principles of digestion management
1. If you don't like what comes out - change what goes in.
2. Treat symptoms as information. When the gastrointestinal tract complains, adjust your child's food intake until the complaints disappear.
The 5 most common infant digestive problems are
All five may occur together and are likely to be food-related. The "irritable" or reactive bowel syndrome begins in infancy with colic, bloating, regurgitation, vomiting and diarrhea. Colic in infancy is abdominal pain with the attendant emotional distress of the infant and his parents. Jenkins et al demonstrated that food allergy is a major cause of infantile colitis.
The combination of gastrointestinal symptoms with congestion, cough, hives, and/or eczema should suggest the diagnosis of food allergy until proven otherwise. The food allergy is likely to be the delayed pattern and will not show up on skin or RAST tests. The diagnosis must be confirmed by proper diet revision, which will resolve the problem if food-related.
Breast-fed infants are exposed to food allergy through their mothers' milk. Harmatz and Bloch stated that: "Infants presenting with manifestations of atopic disease including atopic dermatitis, colic, colitis, or diarrhea and with exclusive breast feeding should be considered to have maternal diet protein-related disease." In their review of the passage on food proteins into mother's milk they stated that measurements of IgE responses (total IgE, IgE RAST and skin tests) were not helpful diagnosing infants who had symptoms from breast milk. Jacobsson and Lindberg demonstrated that cow's milk in the maternal diet can cause colic in breast-fed infants. Lothe et al demonstrated that infantile colic is a symptom of cows milk protein intolerance and remitted when a cows milk formula was replaced with nutramigen, a hypoallergenic formula, based on hydrolysed casein.
A mother may have to retreat to a hypoallergenic diet to rescue her infant from colic with or without more obvious manifestations of food allergy. Adequate nutrition can be supplied by Phase 1 foods (Alpha Nutrition Program) during the 10 days required to clear her infant's symptoms. Exclusion of single high risk food groups such as milk and eggs may not be adequate to solve the infant's problem. Once the infant is comfortable, mother may then reintroduce low risk foods and expand her diet, monitoring her infant for recurrent symptoms.
Diarrhea - Acute Infections
Bout of diarrhea are common in toddlers for food borne infections. In third-world terms, infectious diarrhea is a leading cause of death in children and can be prevented by improvements in water quality, home hygiene, sewage disposal and food handling - all features that affluent communities take for granted.
Water and electrolyte loss is the major cause of death when diarrhea is severe - frequent watery bowel movements can dehydrate and infant and small child quickly. Both sodium and potassium are lost and should be replaced. The treatment is oral dehydration (ORT) - the simplest solution is water as a 0.9 % salt solution by mouth. Commercial products such as pedialyte are used as ORT. Rice water has been effective in third world countries - rice is boiled in large amounts of water ( 6 cups per 1 cup of rice) and the liquid is poured off and fed to the child.
Maximal water absorption occurs when the sodium concentration is 40-90mmol/L and glucose contrition is 110-140mmol/L; the total osmolalility of the solution should be 290mOsm/L. Cola for example has an osmolality of 750 mOsm/L; undiluted apple-juice is 730 mOsm/L - both are too concentrated to feed to a child
Tolerance for Foods
The gastrointestinal tract in normal circumstances learns to tolerate foods that are presented regularly. Oral tolerance to food is learned by infants as solid foods are introduced. In the best case, tolerance to regularly eaten food endures throughout the life of the individual. Infants do best on breast milk for the first six months and develop tolerance to solid foods if the are introduced slowly over the next six months. Some infants are hypersensitive and feeding them is difficult; their tolerance mechanisms do not work very well or are slow to accept new foods. These infants must be fed very carefully and their breast-feeding mothers often have to follow a careful diet to avoid food antigens in the breast milk. More permissive tolerance may not show up until the second year and may be limited for the entire life of that individual.
Many events alter or reduce food tolerance. An infectious gastroenteritis, for example, may leave the gastrointestinal tract in a hypersensitivity state and the patient reports decreased tolerance to many foods. This post-infectious hypersensitivity may lead to chronic "reactive bowel" symptoms.
Gastrointestinal Allergies to Food
In a review of gastrointestinal allergies to food, Walker-Smith and his colleagues stated that:
"Gastrointestinal food allergies may be defined as clinical syndrome which are characterized by the onset of gastrointestinal symptoms following food ingestion where the underlying mechanism is an immunologically mediated reaction within the gastrointestinal tract. There are broadly speaking two categories of clinical syndromes which are related to the speed of onset of symptoms: immediate and delayed. Those syndromes which manifest immediately after food ingestion are easy to diagnose and specific IgE tests and prick tests are frequently positive. Those with a delayed onset of up to several days are difficult to diagnose and currently available investigations may be unsatisfactory for routine use."
Saavedra-Delagado and Metcalfe reviewed mechanisms of food antigens causing gastrointestinal disease. They detailed the pattern of cow's milk induced gastroenteropathy in children, another prototype of food allergic disease, which manifests as chronic diarrhea and is not associated with positive skin tests to cow's milk proteins. They noted associated symptoms included chronic rhinitis and recurrent otitis media.
Moon and Kleinman reviewed allergic gastroenteropathy in children and stated; "The symptoms of allergic gastroenteropathy may be those of classic allergic reactions or present as symptom complexes that may include diarrhea, malabsorption and protein-losing enteropathy." Diarrhea, vomiting, weight loss, abdominal pain and rectal bleeding were the dominate symptoms.
Protein-losing enteropathy occurs in children presents as edema, anemia, and growth failure or weight loss. Food allergy will also cause a non-specific malabsorption syndrome associated with chronic diarrhea. Following an infectious gastroenteritis, both viral and bacterial, hypersensitivity reactions to food are common and in infants may present as a post-enteritis milk-protein intolerance.
Ciprandi and Canonica reported that 132 of 236 patients with cutaneous manifestations of food allergy had gastrointestinal diseases - 17.8% presenting with irritable bowel, 13.5 % with constipation, and 11% with ulcer-like dyspepsia.
Hill and Milla reported thirteen infants with eosinophilic colitis who improved with diet revision. All presented with chronic diarrhea containing bloody mucus before 2 years of age. Colon erythema was noted and biopsies showed inflammatory cell infiltrates in the lamina propria; eosinophils and plasma cells predominated. Cows milk and eggs were routinely excluded from the diet with improvement; 7 children did well on soya formula, but 5 required a chicken-based formula. With food introduction, 7 children developed diarrhea with other foods; beef (3), wheat (3), white flour (1), fish (2), pork (2) and goats milk (1).
Hill et al reported milk allergy in children with cystic fibrosis who continued to have diarrhea and failure to thrive despite adequate treatment with pancreatic enzymes. A proximal small intestine biopsy was used to identify children with milk enteropathy - thinning of the mucosa with reduced villous height were the main findings. They estimated the incidence of milk allergy at 16% in a group of children with cystic fibrosis. The hydrolysed casein formula, Pregestamil, was used as a milk replacement
Some children present with loose and more frequent stools either constantly or intermittently over months to years. Some have episodes of watery stools with urgency, cramps, and bloating. Others have low grade but persistent diarrhea. The differential diagnosis is broad. If weight loss and iron deficiency anemia accompany the diarrhea, Crohn's and Celiac disease must be considered. Diarrhea with blood in the stools always suggests ulcerative colitis. Stool samples for cultures and microscopic examination are essential. The practical point is that most patients with chronic diarrhea will benefit from diet revision. Diet revision will be definitive treatment especially if investigations are negative and no specific remedy can be found. By doing careful diet revision, parents will usually reveal that the child has normal stools with "safe foods" and will generate a list of reactive foods that trigger recurrent diarrhea.
Many children present with constipation with and without episodes of diarrhea. Reduced stool frequency and hard stools are associated with various degrees of abdominal discomfort - usually bloating and distension of the descending colon with accumulating feces. Diet revision using the Alpha Nutrition Program as a guide will often improve bowel function especially if high vegetable and fruit fiber intake is encouraged. Rice tends to be constipating and this effect is balanced by having 2-3 portions of vegetables for each portion of rice. Cow's milk is a major cause of chronic constipation, beginning in infancy. Iacono et al reported that 21 of 27 infants with chronic constipation improved with a milk protein-free diet; 15 of these infants had evidence of milk allergy.