The goal of this clinical trial is to study the efficacy and safety of diluted phosphate enema in treating hypophosphatemia in adults in critical care unit in comparison to intravenous sodium glycero-phosphate as the current standard of care.

The main question it aims to answer is:

can the investigators rely on phosphate enemas as an effective and safe treatment option for hypophosphatemia in critically ill adults, in the era of global shortage of parenteral nutrition solutions and the absence of defined guidelines for treatment of acute hypophosphatemia in those population.

A Randomized Controlled Trial - Non inferiority trial of 2 groups, Eligible participants will be randomly assigned to one of two groups (Intervention Group will receive Diluted Oral phosphate enema as the repletion strategy, while Control Group will receive The Standard of care: intravenous sodium glycerophosphate) for the purpose of treatment of hypophosphatemia in critically ill patients.

Dose Calculation: as per hospital protocol and scientific reference(Crook, 2009) 0.32 mmol per kg for mild hypophosphatemia 0.64 mmol per kg for moderate hypophosphatemia

All participants will be reassessed the next day after the intervention and followed up for the occurrence of any side effects, then participants will be followed up again the day after. (Assessment of serum phosphate and sodium along with occurrence of diarrhea or any other side effects).

Inclusion Criteria:

• Critically ill Patients with mild (2-2.4 mg/dl) to moderate (1.5-1.9 mg/dl) hypophosphatemia.
• Serum phosphorus level less than 2.5mg/dl - between 1.5 - 2.5mg/dl
• Patients 18 years or older

Exclusion Criteria:

• Severe hypophosphatemia
• Serum Phosphorus level less than 1.5 mg/dL
• Patients on Non-peroral status
• Ileus (as paralytic ileus, post-operative)
• Any problem in gut integrity as (intestinal obstruction, Severe Malabsorption, severe diarrhea)
• Any form of ischemic gut (as mesenteric ischemia, mesenteric gastric occlusion, arterial venous insufficiency)
• Hemodynamically unstable patients
• Severe Hypocalcemia or Hypercalcemia at the beginning of the study (when iv phosphate is deemed inappropriate at the discretion of attending physician)