Boris Johnson was admitted to hospital for what No 10 said was a minor and routine operation on his sinuses. The prime minister was put under general anaesthetic and is now resting at home, with Dominic Raab, as deputy prime minister, put in charge of taking any significant decisions while he recovers. Johnson’s spokesperson said whether he would return to work on Tuesday depended on “how he feels” but he was still expected to attend the Commonwealth heads of government meeting in Rwanda later this week. No 10 said the operation was a success and had been scheduled “for a while”. Johnson had been driven to hospital at around 6am on Monday and was returned home by 10am. The procedure was conducted on the NHS and Johnson was “very briefly” unconscious while he had the general anaesthetic administered, the spokesperson said. They refused to answer questions about whether the prime minister had skipped waiting lists of almost 6.5 million people, saying it was not something they would be “getting into”. Asked whether the operation on his sinuses was related to Johnson having caught Covid-19 more than two years ago, the spokesperson said that was “certainly not my understanding”, and added: “I wouldn’t generally comment on the PM’s medical history but obviously it’s of public interest as regards to this operation.” Raab could chair Tuesday’s meeting of the cabinet, which is due to take place in person despite rail strikes, if Johnson is not ready to return to work. If any significant military decisions are taken regarding the war in Ukraine, Johnson is still likely to be consulted but it will be up to Raab to take the final decision. NHS guidance says general anaesthetic can “affect your memory, concentration and reflexes for a day or two, so it’s important for a responsible adult to stay with you for at least 24 hours after your operation”. It adds that patients are advised to “avoid driving, drinking alcohol and signing any legal documents for 24 to 48 hours”. A medical source said it was likely Johnson had had a procedure called functional endoscopic sinus surgery (FESS) to treat chronic sinusitis. The surgeon can widen the patient’s sinuses by either removing some of the blocked tissue or inflating a tiny balloon in the blocked sinuses before removing it. The operation is performed through the nostrils, with no cuts or stitches on the face. Complications were very rare, the source said. Sinusitis is a common condition that involves swelling of the sinuses and is usually caused by an infection. Symptoms include pain, swelling and tenderness around the cheeks, eyes or forehead, a blocked nose, a headache and bad breath. The condition usually clears up on its own within two to three weeks. But medicines are sometimes required if it is taking a long time to go away. In some cases, a GP may refer the patient to an ear, nose and throat (ENT) specialist if, for example, they still have sinusitis after three months of treatment or repeatedly suffer from the condition. The former Labour leader Ed Miliband had ENT surgery in 2011 to correct a deviated septum in an effort to cure his sleep apnoea.