Gastrointestinal bleeding due to telangiectasias: This is the most direct complication related to hereditary hemorrhagic telangiectasia (HHT) that could cause abdominal pain. The presence of telangiectasias in the gastrointestinal tract can lead to bleeding, which may manifest as abdominal pain, among other symptoms.

Liver vascular malformations: Individuals with HHT can have liver involvement, including arteriovenous malformations (AVMs) or telangiectasias, which can cause abdominal pain due to various mechanisms such as shunting, ischemia, or compression effects.
Gastrointestinal ischemia: Although less common, the presence of vascular malformations or telangiectasias can potentially lead to ischemic events in the gastrointestinal tract, causing abdominal pain.

Ruptured hepatic AVM: A potentially life-threatening condition where an arteriovenous malformation in the liver ruptures, leading to severe abdominal pain and potentially hemodynamic instability. Early diagnosis and intervention are crucial.
Bleeding from other visceral AVMs: Similar to hepatic AVMs, AVMs in other abdominal organs (e.g., spleen, intestines) can rupture and cause severe abdominal pain and bleeding.
Pulmonary AVM with paradoxical embolism: Although the primary symptom might not be abdominal pain, the presence of pulmonary AVMs in HHT patients can lead to paradoxical emboli, which can cause abdominal pain if the embolus lodges in abdominal vessels.

Hepatobiliary cysts or other rare liver lesions: While not directly related to the vascular nature of HHT, some patients might have coincidental liver lesions that could cause abdominal pain.
Intestinal obstruction due to chronic bleeding or intussusception: Rarely, chronic bleeding from gastrointestinal telangiectasias could lead to conditions that cause intestinal obstruction, such as intussusception, which would present with abdominal pain.