Omeprazole oral solution is a medication used to treat gastroesophageal reflux disease (GERD), stomach and intestinal ulcers, and other conditions caused by excess stomach acid. According to the sources provided, the time it takes for omeprazole oral solution to work may vary depending on the condition being treated.

The drug patent watch website [1] provides information on the patent status of omeprazole oral solution but does not provide any information on how long it takes for the medication to work.

The Mayo Clinic [2] recommends taking omeprazole oral solution at the same time each day, usually before a meal. It may take several days to a few weeks for the medication to work fully. The medication should be taken for the full prescribed length of time, even if symptoms improve before the medication is finished.

A US Pharmacist article [3] states that omeprazole oral solution may start to work within one to four days of starting treatment. The article also notes that the dosage of omeprazole oral solution may vary depending on the condition being treated and the patient's age and weight.

In summary, the time it takes for omeprazole oral solution to work may vary depending on the condition being treated, but it may take several days to a few weeks for the medication to work fully. It is important to take the medication as prescribed and for the full length of time prescribed, even if symptoms improve before the medication is finished.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/OMEPRAZOLE
[2] https://www.mayoclinic.org/drugs-supplements/omeprazole-oral-route/proper-use/drg-20066836
[3] https://www.uspharmacist.com/article/omeprazole-1-mg-ml-or-2-mg-ml-oral-suspension