Salmonella Colitis: An Important Differential Diagnosis of Inflammatory Bowel Disease

Abstract

26 year old man presented to GI clinic with a complaint of severe bilateral lower abdominal pain associated with fever, night sweats and rectal bleeding for several days. Abdominal pain was sharp, 10/10 in intensity with no obvious relieving and aggravating factors. He had underwent colonoscopy one month previously due to intermittent rectal bleed for several weeks which revealed an anal fissure with no evidence of colitis. Conservative management with suppositories resulted in resolution of bleeding. He was admitted for additional workup. CT scan showed thickening of the left colon extending into recto-sigmoid area. IBD was high in the differential diagnosis. Flexible sigmoidoscopy was done which showed severe ulcerative colitis (UC) in descending and sigmoid colon as well as rectum. He was started on IV Solumedrol empirically. He did not show much improvement over the next 24 hours. On day 2 his stool culture was positive for salmonella species and he was started on Levofloxacin and steroids were stopped. His symptoms improved. Pathology showed acute colitis with no chronic architectural changes. He was discharged on day 4 in clinically stable condition with diagnosis of Salmonella colitis. Follow up in GI clinic showed remarkable improvement. Discussion: Approximately 200 to 300 cases of Salmonella are reported in the USA each year. S. enteritidis, a common cause of foodborne disease outbreaks, is most frequently associated with eggs or egg-containing products. Salmonella infection usually affects the Small Intestine, but it can also affect the colon resulting in diffuse colitis. The colitis may be difficult to differentiate from UC. Stool studies should always be ordered and infectious etiologies should be ruled out, even in patients with known IBD who present with worsening symptoms. Colonoscopy is not necessary for diagnosis of Salmonella Colitis, as diffuse colitis is seen in both UC and Salmonella Colitis. Pathology may assist with the diagnosis, however. Treatment has traditionally been a Fluoroquinolone, but severe cases may require the addition of Ceftriaxone due to increasing resistance patterns. Our case report discusses a young man with symptoms and sigmoidoscopy findings suggestive of UC. Stool studies showed the unexpected presence of salmonella. This case reinforces the importance of stool studies in all patients with abdominal pain and hematochezia, even with a pre-existing diagnosis of IBD.Figure 1