Laxative Abuse and Cathartic Colon Syndrome in Eating Disorders

Monday, April 10, 2017

300300p27278EDNmainMedical Monday Geer 114Feeling full, bloated and constipated is extremely uncomfortable for anyone, but for individuals suffering with an eating disorder this feeling is magnified and can lead to urges to do something to prevent this. Unfortunately, constipation is a common symptom for people suffering from an eating disorder such as anorexia nervosa or those that are at a low body weight from other eating disorders such as ARFID or Avoidant/Restrictive food intake disorder, and can be very distressing to individuals.  When people are at a low body weight their gut slows down, both their stomach, in the form of gastroparesis, but also their small and large bowels, usually in the form of constipation.   Constipation is commonly defined as having less than 3 bowel movements in a 7 day period by Rome III criteria.

As a physician working on ACUTE I frequently see patients who use laxatives to help them have bowel movements in order to prevent constipation, and this should always be done under the supervision of a physician partner because this can quickly escalate to laxative abuse.  When patients are at a low body weight, the intrinsic rhythm, also known as peristalsis, of their small and large bowels is slowed thereby leading to constipation.  Stimulant laxatives work by, as their name implies, stimulating that intrinsic rhythm of the gut to speed up movement of food and stool through the bowels.  The intrinsic rhythm of the bowels is controlled by the myenteric plexus, which is a part of the nervous system that functions independently from the rest of the central nervous system.  With stimulant laxatives, the myenteric plexus gets bombarded with signals to contract, contract, contract, leading to bowel movements.  When fighting an eating disorder, this can feel great, but the short term relief of constipation can lead to a disconnect between the mind and body and the feelings of “constipation” can be misattributed and lead to an ever increasing amount of laxatives, and this is dangerous.   Remember, constipation is defined as less than 3 bowel movements in a week, so having multiple bowel movements a day is not the goal and should not be the goal.  

Over time, higher and higher doses are needed to achieve the same level of effect as the gut gets weary from the constant stimulation and eventually this can lead to a condition called cathartic colon syndrome!  Cathartic colon syndrome is the absence of peristalsis, or that intrinsic rhythm of the bowels so stool just doesn’t move and leads to significant constipation.  This is something that does not respond to medications and does not improve as this is a sign that the intrinsic nervous system of the bowel is burned out, which does not get better.  The only treatment may actually be to surgically remove the colon, so it is of paramount importance that it doesn’t get this far. Laxatives of any kind, osmotic vs stimulant should only be used under the direction of a physician partner and the only treatment that can resolve constipation in the setting of an eating disorder is weight restoration.   At ACUTE we work hard to treat constipation in our patients, as we know that this is one of the most uncomfortable parts of treatment, but we do this in a safe manner and without the use of stimulant laxatives so that we don’t get to the point of cathartic colon syndrome.