A 35-year-old man presented with an indurated tender swelling in his right groin, which had been present for two weeks [UK]. Uncertainty about the diagnosis resulted in early surgical exploration. Although the tissue appeared to be infected, there was minimal pus in the wound. There was neither an inguinal hernia nor any other gross features that may have suggested an aetiology of this infection. Swabs were taken for routine culture, and the wound laid open. No growth of bacteria was present after 7 days of routine culture. The patient was subsequently discharged home with a 7-day course of flucloxacillin. On review, four weeks later, the wound had healed, but he was now complaining of non-specific right hip pain and constipation. Inflammatory markers were checked, but before his scheduled review in six weeks, he presented as an emergency with a 4-week history of colicky abdominal pain, water diarrhoea, and vomiting. On examination, he was distended with obstructive bowel sounds. Plain abdominal X-rays showed dilated loops of small bowel and the impression of a soft tissue mass in the right iliac fossa. An abdominal ultrasound performed demonstrated numerous hypotonic fluid filled small bowel loops and an obstructed right ureteric system. An intravenous pyelogram confirmed that there was a partial obstruction of the right ureter by an extrinsic lesion. As there was no resolution of his small bowel obstruction after 3 days of intravenous antibiotics and there was concern about the underlying diagnosis, an on-table colonoscopy and laparotomy was performed. The histology of the specimen confirmed a chronic inflammatory fibrotic mass in the recto-sigmoid region containing clumps of eosinophilic Gram-positive non-acid fast branching bacteria whose appearance was consistent with Actinomyces. Because of the diagnosis of actinomycosis, he was treated with an additional 10 days of intravenous cefuroxime and metronidazole. His postoperative course was unremarkable, and he was discharged 2 weeks after surgery. He continued with oral augmentin for another 4 weeks and remained well at his 6-week follow-up appointment.