Hi,
Welcome back to icliniq.com.
I went through your detailed clinical summary and queries.
First of all, make it clear that IBS (irritable bowel syndrome) and SIBO (small intestinal bacterial outgrowth) diagnose exclusion, i.e., diagnosed only after ruling out other common treatable conditions. IBS can range in severity and nature of symptoms in each person.
I am going through your queries.
I would suggest you not to get into the neurologic/ bacteriologic basis of these symptoms. It will add more confusion to you. These things are still under research, and you can get varied information. Bowel frequency can vary widely form three times a day to three times a week. Similarly is the occurrence of gas. These are quite natural symptoms.
Please avoid manual stimulation as this is dangerous and can be habit-forming. Your morning bowel movements themselves show that you have an excellent natural movement. There will be some stools in the rectum (colonic reservoir before the anus), which is natural. This can, at times, cause increased flatulence and an urge to defecate.
Endoscopy examines the stomach and proximal small intestine. Colonoscopy examines from distally the large intestine. There is a long segment of the small intestine in between, which cannot be usually examined by these tests. CT enteroclysis is used for getting info regarding this. It is done when you have severe symptoms, any gut obstruction, or if the doctor has any strong clinical suspicion. You can wait as you do not have any such serious complaints as of now.
Bowel distension after passing stools happens very often. It is just the response of the intestine to emptying. Not due to the movement of bacteria, which you won't even feel. Avoid misconceptions, as this will add to your anxiety.
The post-lunch sleepiness is due to high caloric lunch resulting in increased blood flow to the intestines. This relatively decreases the flow to the rest of the body. The increased gut metabolism and changes in the blood result in these symptoms. You can adjust the lunch volume and nature. Avoid a heavy lunch, rather prefer a short split lunch. Can add more proteins, reducing carbohydrates and fat. But make it clear that adding proteins can increase the flatulence - so a balance needs to be kept.
Advanced tests for SIBO are usually done when we suspect something else so serious which needs to be excluded. For SIBO, the treatment does not change much even if we use these advanced tests. Do not get tensed or anxious, as these are well known to aggravate bowel motility related symptoms. Just relax and lead a stress-free life.
Searching on the internet will add more confusion and anxiety to you as these conditions can have a wide range of manifestations and explanations. You will not get the info relevant in your case. Instead you will be bombarded with unnecessary data.
Have a healthy diet and add regular physical exercises to your routine. Keep yourself well, hydrated.
I hope this helps.