This is a rare but recognised long-term complication of gastrointestinal surgery. This is most commonly found post bariatric surgery, but has also been identified in patients who have had colonic interpositions, particularly those who have had multiple surgeries or interpositions. Uniquely to this group, the blind pouch may occur in either the interposition or (as is more usual) the operated remaining bowel.
In this condition, a small segment of the bowel is bypassed and cut off from the normal flow of food. This can lead to malabsorption and small intestinal bacterial overgrowth (SIBO) syndrome. Obstruction to the normal passage of food through the affected segment leads to ineffective bile salt digestion of fats and fat-soluble vitamins. The stagnant food ferments, with associated bacterial overgrowth. (190)
The blind stump can lead to fat malabsorption and steatorrhoea, and vitamin A and D deficiency from the fat malabsorption. If the bowel wall becomes inflamed, this can also cause malabsorption of carbohydrates and proteins. Vitamin B12, K and iron may become deficient.
Symptoms include bloating and early satiety, dyspepsia, flatulence, diarrhoea and steatorrhoeia, weight loss (sometimes extreme) and nausea. It can also rarely present with ulceration and melaena.
If blind loop syndrome or SIBO is suspected in this patient group, referral to a tertiary centre with knowledge of OA/TOF is recommended. The majority of testing will be done in the hospital setting, but blood testing for deficiencies associated with malabsorption should be done in primary care, including FBC, ferritin, vitamin D levels, INR and calcium levels.
SIBO breath testing is the first-line investigation, but these patients will need in-depth investigation to identify the blind loop, including flexible gastrointestinal endoscopy, capsule endoscopy for the small intestine, CT scans, abdominal X-ray and barium studies.
The ideal treatment is correction of the underlying cause, surgically, but many of these patients are too complex for this to be a safe option. Correction of any malabsorption and nutritional deficiencies is also vital. Long-term antibiotics are the mainstay of treatment, such as tetracyclines, rifaxamin, ciprofloxacin. (190,191,191–194)