History of tonsillectomy is associated with irritable bowel syndrome.

To the Editor: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by altered bowel function, abdominal discomfort, and bloating affecting 20% of individuals worldwide. The diagnosis is based on specific clinical criteria in the absence of a detectable organic cause. Interestingly, there is growing literature that patients with IBS have alterations in intestinal microbiota. The human gut is an elaborate ecosystem composed of 10 bacteria established in the first year of life and continuously altered by exogenous factors; however, genetics significantly contribute as well. The general requirement of intestinal colonization is microbial access to the intestinal tract, counteracted by enzymes, gastric acid, and the mucosal immune system. As microbes enter the human digestive tract, the first major encounter with the host immune system is the tonsils. The tonsils are important sentinels in the detection of foreign antigens/bacteria entering the digestive tract, and their removal may influence bacterial colonization/invasion of the alimentary tract. We examined whether a history of tonsillectomy is associated with the presence of IBS. We utilized a prospectively collected dataset of patients referred to a tertiary medical center. Patients with IBS (Rome I criteria) completed a symptom questionnaire to assess bowel symptoms. Bivariate and multivariate analyses were employed to assess associations between IBS, tonsillectomy, GI symptoms, and demographics. A total of 1125 patients (72% female), mean age 44.4±17.5 years were evaluated. Of these, 530 patients had IBS. A history of tonsillectomy was observed in 59.5% and 40.5% of patients with and without IBS, respectively (P=0.001). Confounding variables associated with IBS included age and sex; after controlling for age and sex, tonsillectomy was significantly associated with IBS (P=0.001). This is the first study demonstrating that tonsillectomy is associated with IBS. The rationale for this relationship is unclear, although we have set forth several hypotheses: the health seeking nature of IBS patients and higher rates of other surgeries may explain the higher rate of tonsillectomy, inflammation of the tonsils. Furthermore, the need for tonsillectomy implies an alteration in the host immune response (also found in IBS patients), and the absence of tonsils may enable successful and undetected pathogen penetration into the intestinal tract leading to postinfectious IBS or even bacterial overgrowth. Further investigation is warranted to understand the novel link between tonsillectomy and IBS.