An Unusual Cause of Lower Gastrointestinal Bleeding
Bibliographic record
Abstract
The most common causes of lower gastrointestinal bleeding (LGIB) are diverticulosis, angiodysplasia, colorectal cancer, inflammatory bowel disease, colonic ischemia, and hemorrhoids.1 In 5% to 10% of cases, a cause is not found; therefore, it is important to be aware of rare causes of LGIB. In this case report, we describe an unusual cause of LGIB in a transplant patient. LGIB, lower gastrointestinal bleeding. A 53-year-old male known for hypertension, chronic renal insufficiency (on hemodialysis), coronary artery disease, and liver transplantation for alcoholic cirrhosis presented to the emergency department because of elevated liver enzymes. He was admitted and treated for obstructive jaundice secondary to a bile duct stricture at the site of the anastomosis. Following endoscopic retrograde cholangiopancreatography and stent insertion, he was kept on his routine immune suppression, which consisted of tacrolimus (Prograf), mycophenolate mofetil, and low-dose steroid therapy. During the course of his hospital stay, he had an episode of tachycardia, mild hypotension, and the passage of large amounts of dark red blood and clots per rectum. There was no abdominal pain or diarrhea. The patient was not known for peptic ulcer disease or nonsteroidal anti-inflammatory drug use but was taking aspirin. His hemoglobin dropped from 90 to 70 g/L. The patient was volume-resuscitated, was transfused, and underwent gastroscopy, which was normal. He subsequently underwent colonoscopy, which demonstrated fresh blood in the cecum. Closer examination revealed a jet of bleeding originating from the orifice of the appendix (Figs. 1 and 2). The cecum was injected with epinephrine in proximity to the appendiceal orifice, and the patient was returned to the floor. However, the patient continued to bleed with significant hemodynamic changes and subsequently underwent superior mesenteric artery angiography. This revealed contrast extravasation from the appendicular artery (Fig. 3), which was subsequently embolized with Gelfoam. Postembolization angiography showed no further blush. Colonoscopic view of blood around appendiceal orifice. Colonoscopic view of jet of blood from the appendiceal orifice. Superior mesenteric artery angiography demonstrating contrast extravasation of the appendicular artery. The patient rebled and became hypotensive the following day, and at this time it was decided to take the patient to the operating room for an open appendectomy. The appendix was removed in the standard fashion. An intraoperative examination of the specimen revealed a 7-mm superficial mucosal tear of the appendix with adherent clot. Pathology confirmed these findings with no associated tumor, malformation, or foreign body. Immunohistochemistry for cytomegalovirus, adenovirus, and Epstein-Barr virus was negative. The patient recovered from his appendectomy uneventfully and did not experience any further episodes of gastrointestinal bleeding. Although LGIB of an appendicular origin is very rare, case reports have been described. The most commonly described causes of appendicular bleeding are Crohn's disease,2-6 diverticular disease,7, 8 acute appendicitis9, 10 and vascular malformations.11, 12 Surprisingly, there are also at least 3 case reports of aorto-appendiceal fistulas as a cause of LGIB.13-15 Less common causes include medication-induced ulcers,16 tumors,17 endometriosis,18 mucoceles,19 and intussusception.20 This case, to the best of our knowledge, is the first report of LGIB from an appendicular source in a liver transplant patient. Transplant patients are at a higher risk of LGIB because of an increased propensity for ulcer formation. Causes include the stress of surgery (if in the early postoperative state) and the use of steroids and nonsteroidal anti-inflammatory drugs as well as the loss of luminal cytoprotection due to immunosuppressive agents such as azathioprine and mycophenolate mofetil.21 The reported incidence of gastrointestinal bleeding in 1000 consecutive liver transplantations was about 0.1%.22 Of these, upper gastrointestinal sources were the most common, and the second most common cause was non-cytomegalovirus enteritis (gastritis, colitis, duodenitis, esophagitis, or ileitis). The most likely cause for this patient's LGIB was a combination of his medications, which included steroids, mycophenolate mofetil, and aspirin. This patient was, however, receiving pantoprozole at the time of his LGIB. In conclusion, this case report reviews the causes of appendicular bleeding and highlights the point that transplant patients are at an increased risk for gastrointestinal bleeding. Ulcer prophylaxis should be considered for transplant patients especially in the early postoperative period and during treatment of rejection.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".