Small Intestine Disorders

The small intestine is approximately 20 feet long and features multiple complex folds, making it inaccessible to standard upper endoscopies (which only reach the duodenum) and colonoscopies (which only view the very end of the ileum). Visualizing the middle sections requires specialized imaging and techniques, such as wireless capsule endoscopy (a swallowable camera pill), double-balloon enteroscopy, or dedicated cross-sectional scans like CT or MR enterography. What are the classic warning signs of a small bowel obstruction?::A small bowel obstruction is a medical emergency characterized by severe, crampy abdominal pain that comes in rhythmic waves, persistent nausea, and vomiting that may become foul or bile-stained. Patients often develop marked abdominal distension and an absolute inability to pass gas or have a bowel movement (obstipation). Previous abdominal surgery is a common risk factor due to internal scar tissue (adhesions). What physical signs indicate that the small intestine is failing to absorb nutrients properly?::Small bowel malabsorption frequently causes chronic diarrhea with pale, greasy, foul-smelling stools that float and are difficult to flush (steatorrhea). Over time, impaired absorption leads to unintended weight loss and distinct deficiency signs, such as brittle nails and fatigue from iron deficiency, easy bruising from low vitamin K, bone thinning from vitamin D and calcium loss, and peripheral neuropathy from vitamin B12 deficiency. What is Small Intestinal Bacterial Overgrowth (SIBO) and how is it evaluated?::SIBO occurs when bacteria that normally reside in the colon migrate or multiply excessively in the small intestine, prematurely fermenting carbohydrates. This causes chronic bloating, excessive gas, abdominal pain, and fluctuating bowel habits. It is most commonly evaluated using a non-invasive lactulose or glucose hydrogen and methane breath test, which measures the concentration of bacterial gases in exhaled breath at set intervals over two to three hours.