Re: Problem with abdominal pain; feel like my intestine is stuck by gallstone.
You can't check the blood pressure of the portal system, however low system pressure when you have abdominal pain can indicate high portal pressure and constipation.
There is plenty of advice available for all condition. Some are for long term and others short term. You appear to have, at present, a short term problem triggered by a liver-flushing event. Doing less often achieves more but other opinions are available.
The key for IBS is to make digestion as easy as possible. This can be achieved by 'food combing', (which is separating protein and carbohydrate); eating warm cooked food, reducing non-soluble fibre, drinking plenty of water and rhythmic exercising such as walking. When this event has passed you can continue with your protocol of choice.
A discharge of toxic bile can upset the balance of bacteria in the gut, and/or change the function of the intestinal wall, and/or disturb enzymes, etc.