Laxative Abuse

Gastrointestinal Interoception in Eating Disorders: Charting a New Path

PURPOSE OF REVIEW

Abnormal interoception has been consistently observed across eating disorders despite limited inclusion in diagnostic conceptualization. Using the alimentary tract as well as recent developments in interoceptive neuroscience and predictive processing as a guide, the current review summarizes evidence of gastrointestinal interoceptive dysfunction in eating disorders.

RECENT FINDINGS

Eating is a complex process that begins well before and ends well after food consumption. Abnormal prediction and prediction-error signals may occur at any stage, resulting in aberrant gastrointestinal interoception and dysregulated gut sensations in eating disorders. Several interoceptive technologies have recently become available that can be paired with computational modeling and clinical interventions to yield new insights into eating disorder pathophysiology. Illuminating the neurobiology of gastrointestinal interoception in eating disorders requires a new generation of studies combining experimental probes of gut physiology with computational modeling. The application of such techniques within clinical trials frameworks may yield new tools and treatments with transdiagnostic relevance.

Laxative abuse: epidemiology, diagnosis and management

Laxatives have been used for health purposes for over 2000 years, and for much of that time abuse or misuse of laxatives has occurred. Individuals who abuse laxatives can generally be categorized as falling into one of four groups. By far the largest group is made up of individuals suffering from an eating disorder such as anorexia or bulimia nervosa. The prevalence of laxative abuse has been reported to range from approximately 10% to 60% of individuals in this group. The second group consists of individuals who are generally middle aged or older who begin using laxatives when constipated but continue to overuse them. This pattern may be promulgated on certain beliefs that daily bowel movements are necessary for good health. The third group includes individuals engaged in certain types of athletic training, including sports with set weight limits. The fourth group contains surreptitious laxative abusers who use the drugs to cause factitious diarrhoea and may have a factitious disorder. Normal bowel function consists of the absorption of nutrients, electrolytes and water from the gut. Most nutrients are absorbed in the small intestine, while the large bowel absorbs primarily water. There are several types of laxatives available, including stimulant agents, saline and osmotic products, bulking agents and surfactants. The most frequently abused group of laxatives are of the stimulant class. This may be related to the quick action of stimulants, particularly in individuals with eating disorders as they may erroneously believe that they can avoid the absorption of calories via the resulting diarrhoea. Medical problems associated with laxative abuse include electrolyte and acid/base changes that can involve the renal and cardiovascular systems and may become life threatening. The renin-aldosterone system becomes activated due to the loss of fluid, which leads to oedema and acute weight gain when the laxative is discontinued. This can result in reinforcing further laxative abuse when a patient feels bloated and has gained weight. Treatment begins with a high level of suspicion, particularly when a patient presents with alternating diarrhoea and constipation as well as other gastrointestinal complaints. Checking serum electrolytes and the acid/base status can identify individuals who may need medical stabilization and confirm the severity of the abuse. The first step in treating laxative misuse once it is identified is to determine what may be promoting the behaviour, such as an eating disorder or use based on misinformation regarding what constitutes a healthy bowel habit. The first intervention would be to stop the stimulant laxatives and replace them with fibre/osmotic supplements utilized to establish normal bowel movements. Education and further treatment may be required to maintain a healthy bowel programme. In the case of an eating disorder, referral for psychiatric treatment is essential to lessen the reliance on laxatives as a method to alter weight and shape.

The eating disorders medicine cabinet revisited: a clinician's guide to ipecac and laxatives

OBJECTIVE

To describe the frequency of alternative medication use in bulimia nervosa (BN), and to review available nonprescription emetic (ipecac) and laxative products and their potential toxicities.

METHOD

Survey data were collected from 39 consecutive treatment-seeking patients with BN or subthreshold BN. Survey data of the available nonprescription and herbal products from local retail stores were also collected. Toxicology information was reviewed on these agents from MEDLINE and herbal textbooks.

RESULTS

Ipecac use occurred in 18% of the 39 patients. Laxatives had been used at some point to control weight or "get rid of food" by 67% of the patients. Of these, 31% had abused laxatives during the month prior to evaluation. In the product survey, 248 laxative-containing products were identified.

CONCLUSION

There are numerous laxative products readily available to patients, and many of them have significant associated toxicities. Patients with BN tend to endorse high rates of laxative use. While ipecac is used infrequently, it can have deleterious consequences. Patients with BN should be screened for use of both ipecac and laxatives and should be educated about the potential consequences associated with the misuse of these agents.

Laxative withdrawal in eating disorders: treatment protocol and 3 to 20-month follow-up

OBJECTIVE

This article describes a treatment protocol for laxative withdrawal and presents some preliminary information about response to treatment at 3 to 20-month follow-up.

METHOD

Patients were contacted 3 to 20 months after admission and evaluated with a shortened form of the Eating Disorders Examination (EDE).

RESULTS

Fifty-seven percent of patients were abstinent from laxatives at follow-up and there were significant reductions in laxative-related symptom variables. Abstinence from laxatives was not accompanied by any other changes in eating behavior and was not associated with any pretreatment variables that were assessed.

DISCUSSION

It appears to be feasible to withdraw patients from laxatives as an isolated intervention with a reasonably high rate of success.

Incidence of laxative abuse in community and bulimic populations: a descriptive review

Estimates of the incidence of laxative abuse in bulimics and in the community-at-large vary widely for various population samples. This review identified 73 studies in which laxative abuse could be assessed in bulimics, nonbulimics, and the community-at-large. Relative risk values for laxative abuse among population subsamples were estimated by moment methods statistical procedure based on mixed model analysis. Results indicated that the lifetime occurrence for laxative abuse behavior in the community-at-large was 4.18%. Bulimic behavior increased the risk for laxative abuse 3.57-fold to 14.94%. Several methodologic and population parameter characteristics are examined for their select impact on laxative abuse. Review of medical nomenclature for classifying laxative substances, iatragenic effects of laxative abuse, and assessment recommendations are also included.

Toxicoses from over-the-counter human drugs

This article describes the mechanisms, recognition, and management of toxicoses from human over-the-counter (OTC) drugs. Drugs that have been included were chosen because of their potential for toxicosis and the incidence of exposure. Drug groups discussed are cough, cold, and allergy medications, laxatives and cathartics, antacids, antidiarrheal agents, topicals, and vitamin and iron supplements.

Clinicopathological study of a patient with idiopathic villous atrophy and small vessel alterations of the ileum

Ileal villous atrophy with normal proximal small intestinal mucosa is a rare lesion observed in a few diseases. We report here a case of unknown etiology. A 49-year-old woman presented with chronic diarrhea and steatorrhea due to bile acid malabsorption which was strikingly improved by a low-fat diet. Villous atrophy was total or subtotal, but enterocyte alterations were minimal. Crypts were hyperplastic and the lamina propria was infiltrated by lymphocytes and plasma cells mainly synthesizing IgM. These alterations were associated with the presence in the submucosa, and occasionally in the mucosa, of numerous convoluted nonectasic capillary tufts. Thrombi consisting of pure platelet aggregates were found in the capillary tufts and adjacent small vessels, whose walls were either normal or hyalinized. The patient suffered for many years from attacks of Raynaud's phenomenon and platelet aggregation was depressed in the presence of collagen. Thrombi disappeared after aspirin treatment, but the other lesions persisted at the time of death from an unrelated cause.

Severe idiopathic constipation is associated with a distinctive abnormality of the colonic myenteric plexus

We analyzed the clinical, radiographic, esophageal manometric, and pathologic features of 26 women with severe, idiopathic constipation. Twenty-four patients were between 19 and 39 yr of age. Stool frequency was once every 5-28 days. On barium enema examination, 9 of 24 patients had colons of increased length and 4 of these 9 patients had colons of increased width (greater than 10 cm). Radionuclide solid-meal gastric-emptying studies were normal in 23 patients tested. Esophageal manometry demonstrated high-amplitude waves in 10 of 22 patients and long-duration waves in 3 of these 10 patients. Rectal biopsy specimens showed normal submucosal neurons in all patients and melanosis coli in 6. Twelve patients underwent subtotal colectomies for constipation. Conventional light microscopy using hematoxylin and eosin serial sections showed (a) melanosis coli in 4 patients; (b) normal smooth muscle in 11; (c) thinning of the circular muscle in 1; and (d) no apparent abnormalities of the myenteric plexus in any. In contrast, silver stains of the myenteric plexus showed (a) quantitatively reduced numbers of argyrophilic neurons in 10 patients; (b) morphologically abnormal argyrophilic neurons in 11; (c) decreased numbers of axons in 11; and (d) increased numbers of variably sized nuclei within ganglia in all 12. A coded analysis of the silver stains of colons from 8 patients with constipation and 19 control cases demonstrated that the pathologic abnormalities of severe idiopathic constipation could be differentiated from controls. Thus, severe idiopathic constipation is associated with a pathologically identifiable abnormality of the myenteric plexus. This abnormality appears different from anything previously described in intestinal pseudoobstruction.

Case report. Tumoral calcinosis: an unusual complication of the laxative abuse syndrome

A 47-year-old woman who abused laxatives as a means of weight control is described. Her laxative abuse resulted in an episode of tetany for which she was given long-term calcium and vitamin D therapy. This therapy, along with the ingestion of absorbable phosphate and alkali, and large amounts of milk, led to the development of tumoral calcinosis. The failure to fully appreciate the contribution of laxative abuse in her metabolic imbalance resulted in this complication.

Bulk laxative ileus

In an elderly nursing home resident who had taken excessive dosages of bulk laxative for many years, small-bowel obstruction developed, requiring surgical intervention. A carcinoma of the ascending colon probably was the immediate cause of the obstruction, which resulted in the accumulation and inspissation of the bulk laxative throughout the small bowel. Great care should be exercised in the long-term use of these laxatives.