Your symptoms sound most consistent with constipation and trapped gas; gallbladder surgery several months ago is unlikely to be the direct cause. Increase water, add fibre gradually and walk daily, but avoid repeated laxatives without advice. If this persists, you need an examination and medication review.
Next Steps
Seek urgent care if you develop severe or worsening pain, repeated vomiting, marked swelling, blood in stool, fever, or cannot pass gas. Otherwise arrange a review soon; you can book an online consultation on Practo for tailored treatment.