Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Emergency assessment is appropriate for severe pain, fainting, confusion, trouble breathing, rapidly worsening weakness, or signs of shock such as cold skin and reduced alertness.
Contact the treating team promptly if the tube stops draining unexpectedly, falls out, leaks around the skin, or causes increasing redness or pain.
Also report a returning fever, worsening abdominal symptoms, repeated vomiting, inability to take medicines, or new drainage from a wound.
And for anyone, someone who:
Follow-up is important after drainage, surgery, or antibiotic treatment.
The care team may review pain, fever, appetite, bowel and bladder function, the surgical wound, and laboratory results.
Repeat imaging is not needed in every case, but it may be used when symptoms do not improve, return, or suggest that fluid remains.
Routine follow-up may include deciding when to remove a catheter, completing antibiotic treatment, and addressing the underlying cause.
For example, a person may need later care for Crohn’s disease, diverticular disease, or a surgical bowel leak.
Some procedures are delayed until the infection and inflammation have settled.
The article also says
If a drainage catheter is in place, follow the specific instructions for emptying the collection bag, recording the amount and appearance of fluid, flushing the tube if instructed, and keeping the dressing clean.
Do not pull, clamp, or remove the catheter unless the care team directs you to do so.
Every sign above is quoted from the sofidex article on Abscess - abdomen or pelvis. If you are not sure, err upward — it is always reasonable to be checked.