Bulimia Nervosa and the Abuse of Stimulant Laxatives

Monday, June 26, 2017

300300p27278EDNmainACUTE1706 03 MedicalMonday S GibsonBulimia nervosa is a medical illness associated with binge eating episodes frequently followed by purging. Although purging can be accomplished through many behaviors and medications, laxatives have been found to be used by up to 75% of those suffering from this condition, with stimulant laxatives being the most commonly abused class of laxatives. Some of the more commonly known stimulant laxatives are Bisacodyl and Senna, both of which can be purchased over the counter, making it easy to abuse these medications. However, abuse of this class of medications can be associated with numerous medical complications. 

 The systemic effects of abusing the stimulant laxatives include electrolyte disturbances, volume depletion, severe edema, and renal malfunction. Hypokalemia is the most frequent electrolyte deficiency seen with laxative abuse. Hypokalemia has a variety of manifestations but most commonly include muscle weakness, paresthesias, and cardiac arrhythmias.

Death could even ensue if levels are low enough. Severe edema may develop due to a condition known as Pseudo-Bartter’s syndrome is where the renin-angiotensin-aldosterone system is highly up-regulated, causing individuals to reabsorb sodium and fluid. Renal malfunction may contribute to kidney stones, muscle breakdown, further electrolyte abnormalities, and in severe cases, hemodialysis may be needed short term or indefinitely.

 The gastrointestinal complications associated with stimulant laxatives include severe diarrhea. Often individuals suffering from bulimia may increase the frequency of laxative use as this is thought to further increase weight loss. However, the amount of nutrient malabsorption is minimal with this method as the laxatives tend to work in the colon, past the point of nutrient absorption. This will only lead to further dehydration and systemic effects as stated above.

 One complication associated solely with stimulant laxatives, specifically Senna, is melanosis coli. The stimulant laxatives seem to work by inducing low grade inflammation in the bowel. The surface cells die off (a process called apoptosis) and a black pigmentation is produced in the bowel as these dead cells are metabolized. This condition is associated with no ill health effects.

 One other condition that has been reported with stimulant laxatives and is much more serious is cathartic colon. In this condition, the colon basically becomes an inert tube, incapable of peristalsis. Bulimics will often further increase dosing of the laxatives to try and counteract this condition, creating a positive feedback cycle. If use of the stimulant laxatives is stopped, this condition can be reversible.

However, continued use of the laxatives may result in irreversible damage to the colon. There are some older reports of women whom had been abusing stimulant laxatives requiring colectomy due to this condition.