Odorous stools, laboratory abnormalities after gastric bypass surgery

A patient comes to her yearly nutrition check-up 11 years after undergoing gastric bypass surgery with reports of loose stools with significant odor several times per day.
A patient comes to her yearly nutrition check-up 11 years after undergoing gastric bypass surgery with reports of loose stools with significant odor several times per day.

Mrs. M is a 46-year-old woman being seen for a yearly nutrition follow-up visit after undergoing open Roux-en-Y gastric bypass surgery 11 years ago. She was last seen approximately 1 year ago for post bariatric surgery care.

Weight history 

  • Weight at time of bariatric surgery: 134.7 kg
  • Weight at approximately 1 year post bariatric surgery: 72.6 kg
  • Weight today: 73.1 kg (61.6 kg lost since surgery)
  • Pre bariatric surgery body mass index: 51.3 kg/m2
  • Current body mass index: 29.1 kg/m2 

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Current diet

Mrs. M reports that she has 3 meals and 2 snacks daily. She denies any food intolerance or allergies. She drinks >64 ounces of water and 24 ounces of milk daily. Protein sources include eggs, cheese, cottage cheese, bacon, chicken, and fish. She does not currently take any protein supplements but typically consumes about 70 grams of protein daily. She eats at a restaurant approximately once a week.

Alcohol: The patient consumes alcohol approximately 1 time per week, usually 2 to 3 beers in one sitting. She understands that she needs to drink no more than 2 to 4 drinks per week, and preferably no more than 2 drinks per day. 

Tobacco: The patient was smoking approximately 5 cigarettes per day until 1 month previously, when she quit smoking.

Nonsteroidal anti-inflammatory drugs: The patient denies use. 

Gastrointestinal symptoms

Mrs. M has loose stools with significant odor 2 to 3 times per day. She reports that this has not changed for the last 10 years. Her bowel movements can be urgent in nature. She has not had formed stools since undergoing bariatric surgery. She denies that consumption of any particular food worsens her stool pattern. 

Exercise/activity program

Mrs. M walks 5 days per week for approximately 45 minutes per day and lifts weights 3 times per week for 20 minutes per day.

Laboratory values

  • Hemoglobin: 11.7 g/dL (normal: 12-15.5 g/dL)
  • Vitamin B12: 312 ng/L (normal 180-914 ng/L)
  • Ferritin: 48 μg/L (normal 11-307 μg/L)
  • Vitamin D: 27 ng/dL (normal 20-50 ng/dL)
  • Vitamin A: 32.1 μg/dL (normal 32.5-78 μg/dL)
  • Vitamin E: 2.0 mg/L (5.5-17 mg/L)
  • Calcium: 8.8 mg/dL (8.9-10.1 mg/dL)
  • Glucose: 91 mg/dL (normal 70-100 mg/dL)
  • Hemoglobin A1c: 4.3% (normal 4%-6%)
  • Aspartate aminotransferase: 23 U/L (normal 8-43 U/L)
  • Albumin: 3.2 U/L (normal 3.5-5 U/L)
  • Bone alkaline phosphatase: 14 μg/L (normal < 20 μg/L)
  • 24-hour urine calcium: 80 mg/24 hour (80-200 mg/24 hour)

Current vitamin supplementation

  • Calcium plus vitamin D: 600/500 mg twice daily with meals
  • Complete multivitamin/multimineral: twice daily 
  • Vitamin A: 25,000 units once daily
  • Vitamin B12: 1000 units subcutaneously once monthly
  • Vitamin D: 50,000 units twice weekly
  • Vitamin E: 400 units once daily
  • Vitron C: 65-125 mg once daily at bedtime

The patient reports consistent use of vitamin supplementation. She separates the calcium from all other vitamins and takes it with meals for better absorption. She reports rarely missing a vitamin supplement. 

Read the answer for Question 1. 

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