OBJECTIVE

The risk factors and mechanisms that contribute to the occurrence of hemorrhoids are not well understood. The study of the comorbid occurrences of hemorrhoids with other diagnoses in identical patients may point to a common underlying pathophysiology. The present study was undertaken to determine which diagnoses are associated with the occurrence of hemorrhoids.

METHODS

A case-control study compared the occurrence of comorbid diseases in case subjects with hemorrhoids with that of control subjects without hemorrhoids. The case population comprised all patients with hemorrhoids (International Classification of Diseases codes 455.0-455.9), who were discharged from hospitals of the U.S. Department of Veterans Affairs between 1986 and 1996. In a multiple logistic regression analysis, the occurrence of hemorrhoids served as outcome variable, and age, gender, ethnicity, and the comorbid occurrence of other diagnoses served as predictor variables.

RESULTS

A total of 96,314 individual patients with hemorrhoids and the same number of control subjects were identified. In a chart review of a random sample of 100 cases, the diagnosis of hemorrhoids could be confirmed in 97 percent of all instances checked. The variety of diagnoses associated with hemorrhoids could be broken down into five large categories: 1) diseases associated with diarrhea (odds ratio, 1.30; 95 percent confidence interval, 1.27-1.33); 2) spinal cord injuries (odds ratio, 1.17; 95 percent confidence interval, 1.09-1.26); 3) constipation and related diseases (odds ratio, 1.48; 95 percent confidence interval, 1.43-1.54); 4) various types of anorectal diseases (odds ratio, 4.71; 95 percent confidence interval, 4.44-5.0); and 5) conditions that could be considered manifestations or sequelae of the hemorrhoidal disease itself (odds ratio, 3.41; 95 percent confidence interval, 3.30-3.51).

CONCLUSIONS

The types and spectrum of comorbid diagnoses associated with hemorrhoids suggest that an increased tone of the anal sphincter constitutes a common pathophysiologic mechanism for the development of hemorrhoids.