Gastrointestinal (GI) Complications from Eating Disorders

Eating disorders can cause various gastrointestinal problems, such as sialadenosis, gastroparesis, dysphagia and gastroesophageal reflux disease. Disordered eating habits like restriction and purging interfere with normal digestion, leading to constipation, discomfort, and poor nutrient absorption. Most gastrointestinal issues improve with nutrition therapy, while pain relievers, hot packs and antacids can help manage other minor discomforts.

Gastrointestinal Complications & Eating Disorders

Gastrointestinal symptoms are nearly universal among individuals with eating disorders like anorexia nervosa and bulimia nervosa. Studies suggest that up to 99% of those with anorexia nervosa and avoidant restrictive food intake disorder (ARFID) experience a gastrointestinal (GI) issue.^1,2 Both food restriction and purging behaviors can cause serious stress on the gastrointestinal tract, leading to numerous complications of the esophagus, stomach and intestines.

These symptoms can also reinforce the cycle of disordered eating by causing discomfort or anxiety around food. Understanding the complex relationship between GI health and eating disorders is essential for effective diagnosis, treatment and long-term recovery.

How Eating Disorders Affect the GI Tract

Self-induced vomiting

Self-induced vomiting disrupts the coordination of the upper gastrointestinal tract by impairing esophageal motility and weakening the lower esophageal sphincter. Over time, this can lead to delayed gastric emptying and sensations of fullness, reflux and nausea, even without recent vomiting.

Diuretic and laxative use

Using diuretics and laxatives causes an imbalance of fluids and electrolytes, which are essential for the neuromuscular function of the intestines. Long-term use can lead to a loss of normal peristaltic activity, especially in the colon, resulting in dependence on these substances to promote bowel movements. Over time, this weakens the gut’s ability to regulate itself, often leading to constipation, discomfort and pain.

Food restriction & malnutrition

Food restriction and malnutrition reduces gastrointestinal motility, enzyme secretion and mucosal activity as the digestive system adapts to prolonged underuse. This impairs nutrient absorption and causes discomfort when normal nutrition resumes, often resulting in bloating, early satiety and slowed digestion.

Gastrointestinal Complications from Eating Disorders

Chipmunk cheeks

Chipmunk cheeks, also known as sialadenosis, is one of the most common signs of self-induced vomiting. The cause of sialadenosis is unknown, but it’s been proposed that a combination of acinar hypertrophy, dysfunction of postganglionic sympathetic neurons and damaged myoepithelial cells are the cause.^3,4

Gastroparesis

Malnutrition is almost universally followed by gastroparesis, or delayed gastric emptying.⁵ Studies of patients with anorexia nervosa and gastroparesis have found that food remains in the stomach much longer, with one study demonstrating that gastric emptying can take almost twice as long compared to controls.^6,7

Symptoms of gastroparesis include:

• Bloating
• Fullness
• Nausea

Colonic inertia

Excessive and chronic misuse of stimulant laxatives can cause colonic inertia (cathartic colon), a condition where the muscles and nerves of the colon become unable to move stool effectively through the intestines.⁸ It is believed that this results from direct damage to the gut myenteric nerve plexus.

Gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is among the most common complications in patients with eating disorders who purge through self-induced vomiting, although those who restrict without purging also report symptoms of reflux.⁸

Over time, repeated self-induced vomiting can weaken the esophageal sphincter, leading to the reflux of stomach contents into the esophagus and causing symptoms like:

• Heartburn
• Chest pain
• Persistent cough

Superior mesenteric artery (SMA) syndrome

Significant weight loss causes atrophy of the mesenteric fat pad surrounding the SMA, causing the duodenum to become compressed between the abdominal aorta and the superior mesenteric artery. This is associated with abdominal pain after eating, early satiety, nausea and vomiting.⁵

Dysphagia

Patients can experience functional or oropharyngeal dysphagia.⁹

Patients may have difficulty swallowing and moving food, liquids, and saliva down the esophagus. Muscle loss and weakness related to food restriction and significant weight loss can affect the throat muscles responsible for swallowing.⁵

Slow transit constipation

Patients with eating disorders also often report small or infrequent stools.⁵ Similar to the slowed gastric emptying caused by malnutrition, colonic transit also slows down. This can lead to symptoms of constipation, although there can also be a significant functional component to these symptoms.

Starvation hepatitis

Starvation is often linked to a condition called starvation hepatitis, where the liver essentially undergoes autophagy (cell death) to supply nutrients stored in the liver to other organs.¹⁰

Barrett’s esophagus

Because the esophageal mucosa of patients who self-induce vomiting is frequently exposed to acidic vomit, there may be an increased risk of developing Barrett’s esophagus.⁸ Barrett’s esophagus & is a condition in which the lining of the esophagus becomes more like the lining of the small intestine due to repeated exposure to stomach acid. This is a pre-cancerous condition and requires treatment of the underlying cause to help reduce progression.

Mallory-Weiss syndrome

In rare cases, the sudden increase in pressure in the stomach or lower esophagus during vomiting can tear the lining of the upper gastrointestinal tract and cause bleeding.⁸ These tears usually lead to blood-streaked or tinged vomit or small amounts of coffee-ground vomit.⁸

Boerhaave syndrome

Boerhaave Syndrome is a rare and deadly condition resulting in spontaneous perforation of the esophagus primarily when retching or vomiting.⁸ It creates a hole through which contents of the esophagus can pass into the chest (mediastinum), putting patients at risk of infection (mediastinitis) and other complications.

Other gastrointestinal complications

There are other miscellaneous complications that can occur independently or alongside other gastrointestinal complications:

• Sensation of having a lump or something stuck in the throat (globus sensation)
• Chronic cough
• Hoarseness and sore throat
• Indigestion
• Pain with swallowing (odynophagia)
• Irritation of the esophagus (esophagitis)
• Esophageal erosions and ulcers
• Melanosis coli (black discoloration of the intestine)
• Rectal prolapse
• Disorders of gut brain interaction

Treating Gastrointestinal Complications

Nutritional rehabilitation

While the gastrointestinal issues caused by eating disorders can be uncomfortable and distressing, many of them improve greatly with weight gain. Nutritional rehabilitation helps the digestive system regain normal movement, enzyme production and gut function. Without nutritional rehab, problems like bloating, constipation and delayed gastric emptying may continue, making it a vital step for long-term physical and psychological recovery.

Pharmacological intervention

Osmotic laxatives & stool softeners

Osmotic laxatives and stool softeners should be prescribed to gently relieve constipation without stimulating the bowel aggressively while reducing the risk of dependence.

Anatacids

Antacids should be prescribed for eating disorder patients with GERD (gastroesophageal reflux disease) reduce esophageal irritation, promote healing and improve comfort.

Find Help for a Severe Eating Disorder

If you are dealing with severe gastrointestinal issues related to an eating disorder, getting specialized care early is important. Medical stabilization and targeted nutrition support provide a foundation for both physical recovery and emotional healing. With the right guidance and support, symptoms can improve and you can take meaningful steps toward recovery.

Start here with a free assessment.

References

1. H Porcelli, P., Leandro, G., & De Carne, M. (1998). Functional Gastrointestinal Disorders and Eating Disorders: Relevance of the Association in Clinical Management. Scandinavian Journal of Gastroenterology, 33(6), 577–582. https://doi.org/10.1080/00365529850171819
2. I Cooper, M., Collison, A. O., Collica, S. C., Pan, I., Tamashiro, K. L., Redgrave, G. W., Schreyer, C. C., & Guarda, A. S. (2021). Gastrointestinal symptomatology, diagnosis, and treatment history in patients with underweight avoidant/restrictive food intake disorder and anorexia nervosa: Impact on weight restoration in a meal‐based behavioral treatment program. International Journal of Eating Disorders, 54(6), 1055–1062. https://doi.org/10.1002/eat.23535
3. A Coleman, H., Altini, M., Nayler, S., & Richards, A. (1998). Sialadenosis: A presenting sign in bulimia. Head & Neck, 20(8), 758–762. https://doi.org/10.1002/(sici)1097-0347(199812)20:8
4. B Donath, K., & Seifert, G. (1975). Ultrastructural studies of the parotid glands in sialadenosis. Virchows Archiv a Pathological Anatomy and Histology, 365(2), 119–135. https://doi.org/10.1007/bf00432384
5. C Mehler, P. S., & Brown, C. (2015). Anorexia nervosa – medical complications. Journal of Eating Disorders, 3(1). https://www.acute.org/publications/anorexia-nervosa-medical-complications
6. D Stacher, G., Kiss, A., Wiesnagrotzki, S., Bergmann, H., Hobart, J., & Schneider, C. (1986). Oesophageal and gastric motility disorders in patients categorised as having primary anorexia nervosa. Gut, 27(10), 1120–1126. https://doi.org/10.1136/gut.27.10.1120
7. E Robinson, P. H., Clarke, M., & Barrett, J. (1988). Determinants of delayed gastric emptying in anorexia nervosa and bulimia nervosa. Gut, 29(4), 458–464. https://doi.org/10.1136/gut.29.4.458
8. G Nitsch, A., Dlugosz, H., Gibson, D., & Mehler, P. S. (2021). Medical complications of bulimia nervosa. Cleveland Clinic Journal of Medicine, 88(6), 333–343. https://www.acute.org/medical-complications-bulimia-nervosa
9. F Wang, X., Luscombe, G., Boyd, C., Kellow, J., & Abraham, S. (2014). Functional gastrointestinal disorders in eating disorder patients: Altered distribution and predictors using ROME III compared to ROME II criteria. World Journal of Gastroenterology, 20(43), 16293. https://doi.org/10.3748/wjg.v20.i43.16293
10. J Kheloufi, M., Boulanger, C. M., Durand, F., & Rautou, P. (2014). Liver autophagy in anorexia nervosa and acute liver injury. BioMed Research International, 2014, 1–10. https://doi.org/10.1155/2014/701064