Ileus: This condition, characterized by a temporary halt of the normal contractions of the bowel muscles, is a common issue post-surgery, especially after abdominal surgeries like gallbladder removal. The vigorous vomiting and inability to tolerate clear liquids support this diagnosis, as ileus can lead to bowel obstruction symptoms.

Adhesions: These are bands of fibrous tissue that can form between organs or between an organ and the abdominal wall after surgery. They are a common cause of bowel obstruction, especially in someone with a history of abdominal surgery.
Opioid-induced Constipation: Opioids can significantly slow down bowel movements, potentially leading to constipation or even bowel obstruction, especially if the patient is not mobilizing well or is dehydrated.
Gastroenteritis: An infection of the stomach and intestines, which could be exacerbated by or contribute to the inability to tolerate clear liquids and lead to vomiting.

Internal Hernia: Although less common, an internal hernia can occur after surgery and cause bowel obstruction. It's crucial to consider this diagnosis due to its potential severity and need for prompt surgical intervention.
Mesenteric Ischemia: This condition involves insufficient blood flow to the intestines and can be life-threatening. It might present with abdominal pain out of proportion to physical examination findings and could be a complication of surgery or unrelated but coincidental.
Perforation: A hole in the wall of the intestine, which can lead to peritonitis (infection of the abdominal cavity) and is a surgical emergency.

Intussusception: A condition where a part of the intestine slides into an adjacent part, potentially causing bowel obstruction. It's more common in children but can occur in adults, often associated with a lead point like a tumor.
Volvolus: A twisting of a portion of the intestine, which can cut off blood flow and lead to tissue death. It's less common but requires immediate medical attention.
Foreign Body Obstruction: Although rare in adults, it could potentially occur if something was inadvertently left in the abdomen during surgery or if the patient ingested something that caused an obstruction.