More information is needed. You cannot just go by the surgery description line which states colostomy take down, you must read the entire operative report. CPT 44345 describes the revision of a colostomy. If you're talking about a takedown or reversal of a Hartmann's procedure that's completely different. Check the prior surgery/op report. Look at codes 44620 to 44626 for enterostomy closure. The 44626 is the Hartmann reversal. Read to be sure there is a resection and an anastomosis. Code 44625 describes an anastomosis
other than colorectal. Code 44626 is a colorectal anastomosis. This is why it is important to read the entire operative report.
Also, is this procedure being done within the 90 day global period for the intial surgery which created this colostomy? If it is, you will require a modifier 58 on the "takedown" procedure(s). As for the flexible sigmoidoscopy, you can check the CCI edits, or if you have an EncoderPro or CustomCoder program, to see if your sigmoidoscopy is bundled into the surgery and/or if a modifier can be used on the scope. Individual payer policies may vary.
In addition, if this new surgery was a Hartmann reversal - when was the decision for this newer surgery made? Do you have the E&M (probably an office visit) documentation for the decision for this surgery? This may also be billable, perhaps with a modifier 24 if within the global period for the 1st surgery depending on the payer. The reasoning for the modifier 24 on the E&M is because this E&M service was required to determine to proceed with the new takedown surgery. As you know, if the intial decision for takedown surgery was made on the day of (with this type of thing unlikely) or the day before, you will require the modifier 57.
Hope this helped. Anyone can add and/or correct any of my statements, I'd like to see other opinions.
Good luck!