Case Study: Abdominal pain, distention, and constipation
The kidney, ureter, and bladder (KUB) X-ray demonstrates a large bowel obstruction. You should order a CT scan and consult a surgeon.
The KUB shows no distal air in the rectum and dilated loops of large intestine >6 cm. These findings are concerning for a large bowel obstruction. Initial management should include a CT scan of the abdomen and pelvis, nasogastric (NG) tube placement, and surgical consultation. The CT image slice below shows a Spigelian hernia in the left abdominal wall, which was the cause of the bowel obstruction. Interestingly, hernias causing obstruction are not always focally painful, especially in the elderly. The hernia was not reducible, and so the patient was taken urgently to the OR for definitive treatment.
Large bowel obstructions are much less common than small bowel obstructions, primarily because adhesions do not usually cause large bowel obstructions. The presentation usually includes generalized or lower abdominal pain. Vomiting is rare, especially if the ileocecal valve is competent. Because adhesions are seldom the cause, large bowel obstructions rarely resolve spontaneously and typically require urgent surgery or colonoscopy. See the table for more details on causes and treatment of large bowel obstructions.
Brady Pregerson, MD, is an emergency physician at Cedars-Sinai Medical Center in Los Angeles and at Tri-City Medical Center in Oceanside, California.
Table 1. Large bowel obstruction
|Clinical||Pain generalized or in lower abdomen, vomiting late if at all (if ileocecal valve competent)|
|Causes||Tumor, 65%; diverticulitis, 20%; volvulus, 5%; impaction, adhesion, ulcerative colitis, foreign body, hernia|
|Treatment||IV fluid, NG tube, OR vs unprepped colonoscopy. If diameter >10 cm, can perforate|
ReferencePregerson B. Emergency Medicine1-Minute Consult Pocketbook. 5th ed. EMresource.org; 2017.