In 1998 Andrew Wakefield suggested that the measles, mumps, and rubella (MMR) vaccine produced enterocolitis, injuring the gastrointestinal lining of children who would subsequently develop autism. One clear implication of this suggestion was that children with autism should have more gastrointestinal problems than children who are typically developing. A recent study strongly suggests that this is not true. Medical researchers from the Mayo Clinic have shown that children with autism are no more likely to have diarrhea, vomiting, gastroesophageal reflux, or abdominal discomfort than their typically developing peers (Ibrahim et al., 2009). This finding supports earlier research conducted by Black, Kaye, and Jick (2002) who found that children with autism were no more likely to have signs of irritable bowel disorder than their typically developing peers.
The study by Ibrahim and colleagues reviewed historical medical records of 121 children with a valid diagnosis of autism in Minnesota. They then selected two control subjects for each child with autism and similarly reviewed their medical records. Records were reviewed for signs of constipation, diarrhea, gastroesophageal reflux and vomiting, abdominal discomfort and irritability, and feeding issues or food selectivity. One particularly interesting aspect of population-based studies conducted by the Mayo Clinic is that their medical staff provides care for over 95% of the persons who live in Olmsted County, Minnesota. Therefore, they have extensive access to one of the most thorough medical databases in the United States. They did find that there were statistically significant differences in the incidence of constipation and feeding problems but there were no differences in any of the gastrointestinal symptoms that would be associated with enterocolitis.
It is not an unusual or alarming finding that constipation and food selectivity occur more often in children with autism relative to their typically developing peers. A delay in a child learning to toilet independently is a frequently encountered problem with all developmental disabilities and is one of the most commonly reported pediatric problems reported with typically developing children. Moreover, delays in toilet training are usually accompanied by constipation. Ibrahim and colleagues also speculate that selective eating may foster constipation. Furthermore, food selectivity has been reported to occur more often in children with autism by a number of studies (including work conducted at the New England Center for Children; Ahearn et al., 2001). One of the findings of Ahearn et al. was that children who were selective were most likely to selectively consume starchy foods, which can be associated with constipation.
Despite the fact that a number of large scale studies have found with a very high degree of certainty that there is no evidence to suggest that the MMR is associated with autism (e.g., DeStefano and Chen, 1999; Fombonne and Chakrabarti, 2001; Honda et al., 2005; Madsen et al., 2002; Wilson et al., 2003), many have persisted to hold this false belief. Additionally, a number of researchers have failed to replicate Wakefield's initial report of finding measles virus in the guts of children with autism (e.g., Afzal et al., 2006; D'Souza et al., 2006). Before Wakefield declared that the MMR caused autism, he reported that the MMR was associated with Crohn's disease, a particularly difficult to treat gut problem (e.g., Wakefield et al., 1993). Following this report, at least 11 studies have been published that do not support an association between measles and Crohn's disease and Wakefield retracted this suggestion in 1998. If he were genuinely interested in promoting scientific facts, he would retract his suggestion that the MMR can cause autism. Ten of his co-authors have retracted this suggestion. Then again, if he were genuinely interested in scientific discovery, Wakefield would not have accepted a large sum of money from a group of lawyers and parents interested in suing drug companies prior to conducting the research he uses to justify his suggestion that the MMR causes autism.
Afzal et al. (2006). Absence of detectable measles virus genome sequence in blood of autistic
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children with autism or pervasive developmental disorder - not otherwise specified.
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Black, C., Kaye, J., & Jick, H. (2002). Relation of childhood GI disorders to autism: Nested case-control study using data from the UK General Practice Research Database. British
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DeStefano, F., & Chen, R.T. (1999). No evidence for MMR vaccine-associated inflammatory
bowel disease or autism in a 14-year prospective study. Lancet, 351, 1327-28.
D'Souza et al. (2006). No evidence of persisting measles virus in peripheral blood mononuclear
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Fombonne, E., & Chakrabarti, S. (2001). No evidence for a new variant of MMR-induced
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Honda et al. (2005). No effect of MMR withdrawal on the incidence of autism: A total
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Ibrahim et al. (2009). Incidence of gastrointestinal symptoms in children with autism: A
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Wakefield et al. (1993). Evidence of persistent measles virus infection in Crohn's disease.
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