Yes a badly performed circumcision can lead to serious consequences:
Complications of circumcision
This directory contains articles about the complications, risks, adverse effects, and disadvantages of circumcision and their treatments (not including repair of the circumcision itself; see
Foreskin reconstruction). See also
Psychological Impacts of Circumcision.
[SIZE=-1][A] Urethral fistula at frenulum (note probe), probably the result of incisional trauma.
Three-year-old boy with an almost transected glans from circumcision at birth, but parents did not note the abnormality until age 3. Urethra had been completely transected (arrow). [C] Neonate referred immediately after Gomco clamp circumcision in which all the skin of the shaft had been amputated. This is a fairly common complication caused by pulling too much skin up into the clamp and amputating it. Fortunately sometimes there is enough of the mucosal side of the prepuce to fold back to resurface the shaft, but some require a free skin graft. [D] Six-month-old baby was referred after loss of the entire penis from cautery used during circumcision. Evidently both corpora had thrombosed and sloughed, so no phallus remained.[/SIZE]
...The National Organization to Halt the Abuse and Routine Mutilation of Males (NOHARMM) has compiled statistical data on the estimated total number of complications and has made it available on the World Wide Web.
Williams and Kapila estimate that a realistic rate of complications from neonatal circumcision ranges from 2% to 10%. To many men who become aware of the function and value of the prepuce, the fact that this genital sensory organ was amputated from them at birth is itself a complication of circumcision; in which case, the actual complication rate is 100%... For males fortunate enough to survive the surgery without immediate complications, there is a growing awareness among men of other delayed, long-term consequences of neonatal circumcision, which are only now beginning to be documented.
Complications, risks, adverse effects of circumcision