The Colon had an “Air” About It: A Case of Symptomatic Pneumatosis Intestinalis: 914

Purpose: Case: An 87 year-old retired pathologist presented with a change in bowel habits, alternating diarrhea and constipation, of 4 months duration. More recently, he experienced explosive non-bloody diarrhea with up to seven episodes daily, and a significant amount of bloating and flatus that at times was uncontrollable in social settings. He denied any upper GI symptoms or constitutional symptom s such as weight loss or fever. On physical exam, he appeared well and much younger than his stated age. Lab work and stool studies were unremarkable other than a mildly elevated sedimentation rate. Celiac serology was negative. Due to his advanced age, he was treated conservatively and sequentially with a trial of a lactose-free diet, a 2 week course of rifaximin, probiotics, over-the-counter Beano, cholestyramine and pancreatic enzymes with no improvement. After the failure of empiric therapies, EGD with duodenal biopsies was performed and was unremarkable. A colonoscopy, however, showed multiple areas of mucosal edema and polypoid appearing lesions in the transverse, descending colon, and sigmoid colon. Ischemia was considered due to reported intermittent hypotension, however, biopsies of the involved colon showed submucosal giant cell reaction suggestive of pneumatosis coli. CT enterography confirmed extensive left-sided colonic pneumatosis intestinalis (PI). He was then placed on a course of metronidazole. After two weeks with only minimal improvement, he was started on an elemental diet in combination with metronidazole, and his symptoms markedly improved. Discussion: PI is a rare condition marked by gas-filled cysts in the wall of the small or large bowel. It is often a benign and incidental finding, but can cause non-specific bowel symptoms. In some cases, PI may reflect a life-threatening abdominal catastrophe which was not the case in our patient. The etiology is unclear, but may be due to mechanical, biochemical, or bacterial causes. Once an intraabdominal catastrophe has been excluded, a variety of treatment options have been recommended based on a number of small case series including long term antibiotics, elemental diet, high-flow oxygen, hyperbaric oxygen, or endoscopic or surgical therapy. Conclusion: PI can cause gastrointestinal symptoms such as bloating and diarrhea and should be considered in patients who fail conservative treatment. Elemental diets and antibiotics may prove helpful in relieving symptoms presumably by altering the colonic gas producing microflora.