Hi there!
Well, without a detailed clinical evaluation it would be difficult to determine the cause of your symptoms. While the blood in stools could result from the haemorrhoid, possible causes of the gurgling/ diarrhoea that may need to be considered include dietary causes, malsorption syndromes, chronic GI infection, parasitic infestations, GI inflammation, GI motility issues, IBS, micronutrient deficiencies, hormonal/ endocrine imbalance etc. While inflammatory causes and growths/ masses would be ruled out by a colonoscopy/ CT; other possibilities may require to be evaluated for. IBS is largely a diagnosis of exclusion and does not present with any clinical abnormalities. For the time being I would suggest following your GI doctor’s advice and trying anti-spasmodic medications which may help with motility issues and symptomatic control.
Hope this is helpful.
Take care!
PS this all started from what I thought was a "bug" and the rumbling grumbling from that has just never gone away. Very frustrating!