A 62-year-old man has perforated diverticulitis and undergoes an emergent left hemicolectomy with a diverting loop ileostomy. If he has a high output ileostomy and is at risk of diversion colitis, which fatty acids are not being absorbed?
Short-chain fatty acids (acetic acid, butyric acid, and propionic acid) are produced by bacterial fermentation of dietary carbohydrates and are an important source of energy for the colonic mucosa, and metabolism by colonocytes provides energy for processes such as active transport of sodium. Diversion of feces by an ileostomy or colostomy can result in "diversion colitis" which is associated with mucosal atrophy and inflammation.
A 58-year-old mother of 10 suffers from fecal incontinence. Usually, defecation occurs by increased intraabdominal pressure via the Valsalva maneuver, increased rectal contraction, and relaxation of the puborectalis muscle, which forms a "sling" around the distal rectum, forming a relatively acute angle that distributes intra -abdominal forces onto the pelvic floor. With defecation, this angle straightens, allowing downward force to be applied along the axis of the rectum and anal, and opening of the anal canal. A dysfunction at which point of this pathway can lead to fecal incontinence?
Defecation proceeds by coordination of increasing intraabdominal pressure via the Valsalva maneuver, increased rectal contraction, relaxation of the puborectalis muscle, and opening of the anal canal. Impaired continence may result from poor rectal compliance, injury to the internal and/or external sphincter or puborectalis, or nerve damage or neuropathy.
A healthy 48-year-old physician with no family history of cancer and who strictly adheres to a high protein, high fiber diet, exercises five times per week for 50 minutes, and takes vitamin C supplements daily performs a fecal occult blood test (FOBT) on herself and tests positive. Should she have any further colon screening?
Fecal occult blood test (FOBT) has been a nonspecific test for peroxidase contained in hemoglobin; consequently, occult bleeding from any gastrointestinal source will produce a positive result. Similarly, many foods (red meat, some fruits and vegetables, and vitamin C) will produce a false-positive result. Any positive FOBT mandates further investigation, usually by colonoscopy.
A 22-year-old college student presents to clinic with a history of intermittent diarrhea for the past 5 days after returning from Mexico. On further questioning, she has had previous episodes of diarrhea for the past 2 years, unrelated to travel. After a physical examination, what are appropriate tests that should be ordered to appropriately work up this patient?
Stool wet-mount and culture can often diagnose infection. Sigmoidoscopy or colonoscopy can be helpful in diagnosing inflammatory bowel disease or ischemia. However, if the patient has abdominal tenderness, particularly with peritoneal signs, or any other evidence of perforation, endoscopy is contraindicated. For chronic diarrhea tests for malabsorption and metabolic investigations should be conducted along with colonoscopy. Biopsies should be taken even if the colonic mucosa appears grossly normal.
A 76-year-old man undergoes an emergent sigmoidectomy for a perforated colon mass. The surgeon performs a Hartmann procedure and brings up a colostomy. In an emergency setting, where is the most appropriate location to seat a colostomy?
In an emergency operation, like this one, where the stoma site has not been marked, an attempt should be made to place a stoma within the rectus muscle and away from both the costal margin and iliac crest. In emergencies, placement high on the abdominal wall is preferred to a low-lying site.
Click to expand