Letters to the Editor  |   October 2010
Parosmia After Laparoscopic Gastric Bypass and Gastric Banding
Author Affiliations
  • Matthew D. Davidson, DO
    Department of Surgery, Community General Osteopathic Hospital, Harrisburg, Pennsylvania
Article Information
Gastroenterology / Neuromusculoskeletal Disorders
Letters to the Editor   |   October 2010
Parosmia After Laparoscopic Gastric Bypass and Gastric Banding
The Journal of the American Osteopathic Association, October 2010, Vol. 110, 617-618. doi:
The Journal of the American Osteopathic Association, October 2010, Vol. 110, 617-618. doi:
To the Editor:  
We have treated several patients who had undergone laparoscopic gastric bypass or gastric banding surgery and later presented to our emergency department with intolerance to food intake because of nausea and vomiting. After radiologic examinations showed no obstructions, we interviewed these patients and discovered that their food intolerance was related to parosmia or nausea after smelling foods that had given them no problems before surgery. The onset of symptoms in these patients varied from a few months to several years after the bariatric operations. 
Postbariatric-surgery parosmia is a problem that occurs when patients are trying to maintain their nutritional intake but are having trouble doing so because of nausea brought on by the smell of liquids, foods, and oral dietary supplements. Discussions with surgical attending physicians at the hospital revealed that this problem has a low overall rate of occurrence, with most cases happening after gastric bypass rather than gastric banding. Time of onset of symptoms varies from a few months to several years after surgery. In general, the duration of the adverse effects is about 3 months for patients treated at our institution. 
We conducted an extensive search of the literature for studies of changes in eating habits and olfactory function in patients after gastric bypass or gastric banding surgery. We used the MED-LINE and PubMed databases, as well as Google, in our literature search. 
Adami et al1 discussed food aversion resulting from distension of the gastric pouch above the Roux-en-Y limb or above the gastric band. Scruggs et al,2 Benson-Davies and Quigley,3 and Tichansky et al4 described changes in taste acuity after gastric bypass and adjustable gastric banding, but they noted no definite etiologic factor or mechanism for these changes. Richardson et al5 reported increased olfactory dysfunction in patients with a body mass index greater than 45, relative to patients with a body mass index less than 45. However, they did not address postoperative changes in olfactory acuity. Leopold6 noted that causes of olfactory distortion may include upper respiratory infections, head trauma, allergic rhinitis, and chronic rhinosinusitis. Teruhiro et al7 added zinc deficiency and medication adverse effects to that list. We found no articles specifically addressing the occurrence of parosmia or the etiologic factors or mechanisms of parosmia after gastric bypass or gastric banding. 
The purpose of this letter is to bring to light the occurrence of postbariatric-surgery parosmia and the need for studies to find an etiologic factor and mechanism for this condition. At our institution, antiemetic agents are used along with a consultation with the dietary services department to treat patients with postbariatric-surgery parosmia. The typical dietary services recommendation in such cases has been for the patient to mix and match liquid and food intake until an appropriate combination is found that will not cause nausea. 
Adami GF, Gandolfo P, Meneghelli A, Gianetta E, Camerini G, Scopinaro N. Preoperative eating behavior and weight-loss following gastric banding for obesity. Obes Surg. 1996;6(3):244-246.
Scruggs DM, Buffington C, Cowan GS Jr. Taste acuity of the morbidly obese before and after gastric bypass surgery. Obes Surg. 1994;4(1):24-28.
Benson-Davies S, Quigley DR. Food aversions and taste changes following Roux-en-Y gastric bypass surgery. Top Clin Nutr. 2008;23(4):357-363.
Tichansky DS, Boughter JD Jr, Madan AK. Taste change after laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding. Surg Obes Relat Dis. 2006;2(4):440-444.
Richardson BE, Vander Woude EA, Sudan R, Thompson JS, Leopold DA. Altered olfactory acuity in the morbidly obese. Obes Surg. 2004;14(7 ):967-969.
Leopold D. Distortion of olfactory perception: diagnosis and treatment. Chem Senses. 2002;27(7):611-615. Accessed September 30, 2010.
Teruhiro O, Mitsuhiro O, Akira D, et al. Parosmia; modern classification and effective treatment option. Japanese J Rhino.. (2003). ;42(1):23-27.