Cilj: Prikazati slučaj pacijenta s akutnim abdominalnim bolom kojemu je dijagnosticirana tromboza splanhničkog venskog sustava, a uzrok je naknadno dokazana mijeloproliferativna bolest uz JAK2 V617F varijantu sekvence. Prikaz slučaja: 44-godišnji pacijent primljen je u hitnu medicinsku službu zbog akutizacije paraumbilikalnog bola koji je trajao 10-ak dana. U laboratorijskim nalazima bile su povišene vrijednosti alfa amilaze i upalnih parametara, zbog čega je pacijent hospitaliziran. Nativna snimka abdomena i ultrazvuk abdomena pokazivali su meteorizam tankog i debelog crijeva. Zbog nejasne dijagnoze učinjena je i kompjutorizirana tomografija (CT) abdomena koja je pokazala samo zamućeno mezenterijalno masno tkivo u korijenu mezenterija. Trećeg dana hospitalizacije zbog intenzivnijih bolova, koji nisu popustili ni na opiodne analgetike, učinjen je kontrolni CT abdomena koji je pokazivao trombozu v. portae, v. mesentericae superior i v. lienalis. Navedene promjene bile su praćene zadebljanjem stijenke tankog crijeva u smislu kongestije i raslojavanja stijenke, ali bez znakova jasne ishemije, te parcijalnim poremećajima perfuzije jetre uz prisutnost ascitesa. U terapiju je uveden niskomolekularni heparin u punoj dozi uz acetilsalicilnu kiselinu, a zbog dodatnog pogoršanja stanja sa znakovima paralitičkog ileusa i progresijom ishemijskih promjena tankog crijeva učinjena je hitna laparotomija. Za vrijeme hospitalizacije, hematološkom obradom dokazana je JAK2 V617F varijanta sekvence i mijeloproliferativna bolest koja je etiološki čimbenik tromboze portalnog sustava i ishemije crijeva. Zaključak: Uzrok akutnog bola u trbuhu može rijetko biti i tromboza splahničkog sustava, koja u kratkom vremenskom periodu može dovesti do životno ugrožavajućeg stanja.; Aim: To present a patient with acute abdominal pain diagnosed with acute thrombosis of the splannchnic vein system and subsequently diagnosed myeloproliferative disease and JAK2 V617F sequence variant. Case report: A 44-year-old patient was admitted to an emergency medical tract due to the acutization of paraumbilical abdominal pain that was present for 10 days, with mild intensity. In the laboratory findings, elevated values of alpha amylase and inflammatory parameters were elevated, wherefor patient was hospitalized. Native abdominal radiograph and abdominal ultrasound showed meteorism of the small intestine and colone. Due to unclear diagnosis, computerized tomography (CT) of the abdomen was performed, which showed blurred mesenterial fatty tissue at the mesenteric root. On the third day of hospitalization due to intense persistent pain that did not decrease with opioid analgetic threatment, a control CT scan was performed and showed thrombosis of v.Portae, v.Mesentericae superior and v.Lienalis. These changes were followed by thickening of the small intestine wall in terms of congestion and wall layering, but without signs of clear ischemia, and partial liver perfusion disorders in the presence of ascites. Low-molecular heparin was given in the full dose with acetylsalicylic acid, and due to an additional worsening of the condition with signs of paralytic ileus and the progression of ischemic changes in the bowel gland, emergency laparotomy was ordered. During hospitalization, a sequence variant of JAK2 V617F and myeloproliferative disease was confirmed, which is the etiological factor of thrombosis and ischemia of the portal system. Conclusion: The cause of acute abdominal pain may be, rarely, thrombosis of the splanchnic system that can lead to life-threatening condition in a short period of time.